diff --git a/.eslintrc b/.eslintrc
index ef0fe2cd3..03dc596df 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -179,6 +179,18 @@
         "selector": "CallExpression[callee.name='assert'][arguments.length!=2]",
         "message": "`assert()` must always be invoked with two arguments.",
       },
+      {
+        "selector": "CallExpression[callee.name='isCmd'][arguments.length<2]",
+        "message": "Use `instanceof Cmd` rather than `isCmd()` with one argument.",
+      },
+      {
+        "selector": "CallExpression[callee.name='isDict'][arguments.length<2]",
+        "message": "Use `instanceof Dict` rather than `isDict()` with one argument.",
+      },
+      {
+        "selector": "CallExpression[callee.name='isName'][arguments.length<2]",
+        "message": "Use `instanceof Name` rather than `isName()` with one argument.",
+      },
       {
         "selector": "NewExpression[callee.name='Cmd']",
         "message": "Use `Cmd.get()` rather than `new Cmd()`.",
diff --git a/src/core/annotation.js b/src/core/annotation.js
index 0e6792811..34bbe9257 100644
--- a/src/core/annotation.js
+++ b/src/core/annotation.js
@@ -39,7 +39,7 @@ import {
   createDefaultAppearance,
   parseDefaultAppearance,
 } from "./default_appearance.js";
-import { Dict, isDict, isName, Name, Ref, RefSet } from "./primitives.js";
+import { Dict, isName, Name, Ref, RefSet } from "./primitives.js";
 import { BaseStream } from "./base_stream.js";
 import { bidi } from "./bidi.js";
 import { Catalog } from "./catalog.js";
@@ -95,7 +95,7 @@ class AnnotationFactory {
     pageIndex = -1
   ) {
     const dict = xref.fetchIfRef(ref);
-    if (!isDict(dict)) {
+    if (!(dict instanceof Dict)) {
       return undefined;
     }
 
@@ -104,7 +104,7 @@ class AnnotationFactory {
 
     // Determine the annotation's subtype.
     let subtype = dict.get("Subtype");
-    subtype = isName(subtype) ? subtype.name : null;
+    subtype = subtype instanceof Name ? subtype.name : null;
 
     // Return the right annotation object based on the subtype and field type.
     const parameters = {
@@ -128,7 +128,7 @@ class AnnotationFactory {
 
       case "Widget":
         let fieldType = getInheritableProperty({ dict, key: "FT" });
-        fieldType = isName(fieldType) ? fieldType.name : null;
+        fieldType = fieldType instanceof Name ? fieldType.name : null;
 
         switch (fieldType) {
           case "Tx":
@@ -209,7 +209,7 @@ class AnnotationFactory {
   static async _getPageIndex(xref, ref, pdfManager) {
     try {
       const annotDict = await xref.fetchIfRefAsync(ref);
-      if (!isDict(annotDict)) {
+      if (!(annotDict instanceof Dict)) {
         return -1;
       }
       const pageRef = annotDict.getRaw("P");
@@ -636,7 +636,7 @@ class Annotation {
     }
 
     this.borderStyle = new AnnotationBorderStyle();
-    if (!isDict(borderStyle)) {
+    if (!(borderStyle instanceof Dict)) {
       return;
     }
     if (borderStyle.has("BS")) {
@@ -681,7 +681,7 @@ class Annotation {
     this.appearance = null;
 
     const appearanceStates = dict.get("AP");
-    if (!isDict(appearanceStates)) {
+    if (!(appearanceStates instanceof Dict)) {
       return;
     }
 
@@ -691,14 +691,14 @@ class Annotation {
       this.appearance = normalAppearanceState;
       return;
     }
-    if (!isDict(normalAppearanceState)) {
+    if (!(normalAppearanceState instanceof Dict)) {
       return;
     }
 
     // In case the normal appearance is a dictionary, the `AS` entry provides
     // the key of the stream in this dictionary.
     const as = dict.get("AS");
-    if (!isName(as) || !normalAppearanceState.has(as.name)) {
+    if (!(as instanceof Name) || !normalAppearanceState.has(as.name)) {
       return;
     }
     this.appearance = normalAppearanceState.get(as.name);
@@ -912,7 +912,7 @@ class AnnotationBorderStyle {
 
     // Some corrupt PDF generators may provide the width as a `Name`,
     // rather than as a number (fixes issue 10385).
-    if (isName(width)) {
+    if (width instanceof Name) {
       this.width = 0; // This is consistent with the behaviour in Adobe Reader.
       return;
     }
@@ -946,7 +946,7 @@ class AnnotationBorderStyle {
    * @see {@link shared/util.js}
    */
   setStyle(style) {
-    if (!isName(style)) {
+    if (!(style instanceof Name)) {
       return;
     }
     switch (style.name) {
@@ -1055,7 +1055,8 @@ class MarkupAnnotation extends Annotation {
       this.data.inReplyTo = rawIRT instanceof Ref ? rawIRT.toString() : null;
 
       const rt = dict.get("RT");
-      this.data.replyType = isName(rt) ? rt.name : AnnotationReplyType.REPLY;
+      this.data.replyType =
+        rt instanceof Name ? rt.name : AnnotationReplyType.REPLY;
     }
 
     if (this.data.replyType === AnnotationReplyType.GROUP) {
@@ -1265,7 +1266,7 @@ class WidgetAnnotation extends Annotation {
     );
 
     const fieldType = getInheritableProperty({ dict, key: "FT" });
-    data.fieldType = isName(fieldType) ? fieldType.name : null;
+    data.fieldType = fieldType instanceof Name ? fieldType.name : null;
 
     const localResources = getInheritableProperty({ dict, key: "DR" });
     const acroFormResources = params.acroForm.get("DR");
@@ -1306,7 +1307,7 @@ class WidgetAnnotation extends Annotation {
       return formValue
         .filter(item => isString(item))
         .map(item => stringToPDFString(item));
-    } else if (isName(formValue)) {
+    } else if (formValue instanceof Name) {
       return stringToPDFString(formValue.name);
     } else if (isString(formValue)) {
       return stringToPDFString(formValue);
@@ -1418,7 +1419,7 @@ class WidgetAnnotation extends Annotation {
     const { xref } = evaluator;
 
     const dict = xref.fetchIfRef(this.ref);
-    if (!isDict(dict)) {
+    if (!(dict instanceof Dict)) {
       return null;
     }
 
@@ -2085,7 +2086,7 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
     }
 
     const dict = evaluator.xref.fetchIfRef(this.ref);
-    if (!isDict(dict)) {
+    if (!(dict instanceof Dict)) {
       return null;
     }
 
@@ -2131,7 +2132,7 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
     }
 
     const dict = evaluator.xref.fetchIfRef(this.ref);
-    if (!isDict(dict)) {
+    if (!(dict instanceof Dict)) {
       return null;
     }
 
@@ -2158,7 +2159,7 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
         parentBuffer = [`${this.parent.num} ${this.parent.gen} obj\n`];
         writeDict(parent, parentBuffer, parentTransform);
         parentBuffer.push("\nendobj\n");
-      } else if (isDict(this.parent)) {
+      } else if (this.parent instanceof Dict) {
         this.parent.set("V", name);
       }
     }
@@ -2250,12 +2251,12 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
 
   _processCheckBox(params) {
     const customAppearance = params.dict.get("AP");
-    if (!isDict(customAppearance)) {
+    if (!(customAppearance instanceof Dict)) {
       return;
     }
 
     const normalAppearance = customAppearance.get("N");
-    if (!isDict(normalAppearance)) {
+    if (!(normalAppearance instanceof Dict)) {
       return;
     }
 
@@ -2318,21 +2319,21 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
     // The parent field's `V` entry holds a `Name` object with the appearance
     // state of whichever child field is currently in the "on" state.
     const fieldParent = params.dict.get("Parent");
-    if (isDict(fieldParent)) {
+    if (fieldParent instanceof Dict) {
       this.parent = params.dict.getRaw("Parent");
       const fieldParentValue = fieldParent.get("V");
-      if (isName(fieldParentValue)) {
+      if (fieldParentValue instanceof Name) {
         this.data.fieldValue = this._decodeFormValue(fieldParentValue);
       }
     }
 
     // The button's value corresponds to its appearance state.
     const appearanceStates = params.dict.get("AP");
-    if (!isDict(appearanceStates)) {
+    if (!(appearanceStates instanceof Dict)) {
       return;
     }
     const normalAppearance = appearanceStates.get("N");
-    if (!isDict(normalAppearance)) {
+    if (!(normalAppearance instanceof Dict)) {
       return;
     }
     for (const key of normalAppearance.getKeys()) {
@@ -2566,7 +2567,8 @@ class PopupAnnotation extends Annotation {
     }
 
     const parentSubtype = parentItem.get("Subtype");
-    this.data.parentType = isName(parentSubtype) ? parentSubtype.name : null;
+    this.data.parentType =
+      parentSubtype instanceof Name ? parentSubtype.name : null;
     const rawParent = parameters.dict.getRaw("Parent");
     this.data.parentId = rawParent instanceof Ref ? rawParent.toString() : null;
 
diff --git a/src/core/catalog.js b/src/core/catalog.js
index 662f4012f..edaec0547 100644
--- a/src/core/catalog.js
+++ b/src/core/catalog.js
@@ -120,7 +120,7 @@ class Catalog {
     let collection = null;
     try {
       const obj = this._catDict.get("Collection");
-      if (isDict(obj) && obj.size > 0) {
+      if (obj instanceof Dict && obj.size > 0) {
         collection = obj;
       }
     } catch (ex) {
@@ -136,7 +136,7 @@ class Catalog {
     let acroForm = null;
     try {
       const obj = this._catDict.get("AcroForm");
-      if (isDict(obj) && obj.size > 0) {
+      if (obj instanceof Dict && obj.size > 0) {
         acroForm = obj;
       }
     } catch (ex) {
@@ -208,7 +208,7 @@ class Catalog {
    */
   _readMarkInfo() {
     const obj = this._catDict.get("MarkInfo");
-    if (!isDict(obj)) {
+    if (!(obj instanceof Dict)) {
       return null;
     }
 
@@ -249,7 +249,7 @@ class Catalog {
    */
   _readStructTreeRoot() {
     const obj = this._catDict.get("StructTreeRoot");
-    if (!isDict(obj)) {
+    if (!(obj instanceof Dict)) {
       return null;
     }
     const root = new StructTreeRoot(obj);
@@ -259,7 +259,7 @@ class Catalog {
 
   get toplevelPagesDict() {
     const pagesObj = this._catDict.get("Pages");
-    if (!isDict(pagesObj)) {
+    if (!(pagesObj instanceof Dict)) {
       throw new FormatError("Invalid top-level pages dictionary.");
     }
     return shadow(this, "toplevelPagesDict", pagesObj);
@@ -283,7 +283,7 @@ class Catalog {
    */
   _readDocumentOutline() {
     let obj = this._catDict.get("Outlines");
-    if (!isDict(obj)) {
+    if (!(obj instanceof Dict)) {
       return null;
     }
     obj = obj.getRaw("First");
@@ -376,7 +376,7 @@ class Catalog {
    */
   _readPermissions() {
     const encrypt = this.xref.trailer.get("Encrypt");
-    if (!isDict(encrypt)) {
+    if (!(encrypt instanceof Dict)) {
       return null;
     }
 
@@ -529,9 +529,10 @@ class Catalog {
       creator: isString(config.get("Creator"))
         ? stringToPDFString(config.get("Creator"))
         : null,
-      baseState: isName(config.get("BaseState"))
-        ? config.get("BaseState").name
-        : null,
+      baseState:
+        config.get("BaseState") instanceof Name
+          ? config.get("BaseState").name
+          : null,
       on: parseOnOff(config.get("ON")),
       off: parseOnOff(config.get("OFF")),
       order: parseOrder(config.get("Order")),
@@ -654,7 +655,7 @@ class Catalog {
       const labelDict = nums.get(i);
 
       if (labelDict !== undefined) {
-        if (!isDict(labelDict)) {
+        if (!(labelDict instanceof Dict)) {
           throw new FormatError("PageLabel is not a dictionary.");
         }
 
@@ -667,7 +668,7 @@ class Catalog {
 
         if (labelDict.has("S")) {
           const s = labelDict.get("S");
-          if (!isName(s)) {
+          if (!(s instanceof Name)) {
             throw new FormatError("Invalid style in PageLabel dictionary.");
           }
           style = s.name;
@@ -743,7 +744,7 @@ class Catalog {
     // affect the Scroll mode (continuous/non-continuous) used in Adobe Reader.
     let pageLayout = "";
 
-    if (isName(obj)) {
+    if (obj instanceof Name) {
       switch (obj.name) {
         case "SinglePage":
         case "OneColumn":
@@ -761,7 +762,7 @@ class Catalog {
     const obj = this._catDict.get("PageMode");
     let pageMode = "UseNone"; // Default value.
 
-    if (isName(obj)) {
+    if (obj instanceof Name) {
       switch (obj.name) {
         case "UseNone":
         case "UseOutlines":
@@ -799,7 +800,7 @@ class Catalog {
     const obj = this._catDict.get("ViewerPreferences");
     let prefs = null;
 
-    if (isDict(obj)) {
+    if (obj instanceof Dict) {
       for (const key in ViewerPreferencesValidators) {
         if (!obj.has(key)) {
           continue;
@@ -921,7 +922,7 @@ class Catalog {
     const obj = this._catDict.get("OpenAction");
     const openAction = Object.create(null);
 
-    if (isDict(obj)) {
+    if (obj instanceof Dict) {
       // Convert the OpenAction dictionary into a format that works with
       // `parseDestDictionary`, to avoid having to re-implement those checks.
       const destDict = new Dict(this.xref);
@@ -1337,7 +1338,7 @@ class Catalog {
           if (
             isRefsEqual(kidRef, pageRef) &&
             !isDict(node, "Page") &&
-            !(isDict(node) && !node.has("Type") && node.has("Contents"))
+            !(node instanceof Dict && !node.has("Type") && node.has("Contents"))
           ) {
             throw new FormatError(
               "The reference does not point to a /Page dictionary."
@@ -1346,7 +1347,7 @@ class Catalog {
           if (!node) {
             return null;
           }
-          if (!isDict(node)) {
+          if (!(node instanceof Dict)) {
             throw new FormatError("Node must be a dictionary.");
           }
           parentRef = node.getRaw("Parent");
@@ -1356,7 +1357,7 @@ class Catalog {
           if (!parent) {
             return null;
           }
-          if (!isDict(parent)) {
+          if (!(parent instanceof Dict)) {
             throw new FormatError("Parent must be a dictionary.");
           }
           return parent.getAsync("Kids");
@@ -1379,7 +1380,7 @@ class Catalog {
             }
             kidPromises.push(
               xref.fetchAsync(kid).then(function (obj) {
-                if (!isDict(obj)) {
+                if (!(obj instanceof Dict)) {
                   throw new FormatError("Kid node must be a dictionary.");
                 }
                 if (obj.has("Count")) {
@@ -1430,7 +1431,7 @@ class Catalog {
    */
   static parseDestDictionary(params) {
     const destDict = params.destDict;
-    if (!isDict(destDict)) {
+    if (!(destDict instanceof Dict)) {
       warn("parseDestDictionary: `destDict` must be a dictionary.");
       return;
     }
@@ -1444,14 +1445,14 @@ class Catalog {
     let action = destDict.get("A"),
       url,
       dest;
-    if (!isDict(action)) {
+    if (!(action instanceof Dict)) {
       if (destDict.has("Dest")) {
         // A /Dest entry should *only* contain a Name or an Array, but some bad
         // PDF generators ignore that and treat it as an /A entry.
         action = destDict.get("Dest");
       } else {
         action = destDict.get("AA");
-        if (isDict(action)) {
+        if (action instanceof Dict) {
           if (action.has("D")) {
             // MouseDown
             action = action.get("D");
@@ -1463,9 +1464,9 @@ class Catalog {
       }
     }
 
-    if (isDict(action)) {
+    if (action instanceof Dict) {
       const actionType = action.get("S");
-      if (!isName(actionType)) {
+      if (!(actionType instanceof Name)) {
         warn("parseDestDictionary: Invalid type in Action dictionary.");
         return;
       }
@@ -1508,7 +1509,7 @@ class Catalog {
 
         case "GoToR":
           const urlDict = action.get("F");
-          if (isDict(urlDict)) {
+          if (urlDict instanceof Dict) {
             // We assume that we found a FileSpec dictionary
             // and fetch the URL without checking any further.
             url = urlDict.get("F") || null;
@@ -1519,7 +1520,7 @@ class Catalog {
           // NOTE: the destination is relative to the *remote* document.
           let remoteDest = action.get("D");
           if (remoteDest) {
-            if (isName(remoteDest)) {
+            if (remoteDest instanceof Name) {
               remoteDest = remoteDest.name;
             }
             if (isString(url)) {
@@ -1540,7 +1541,7 @@ class Catalog {
 
         case "Named":
           const namedAction = action.get("N");
-          if (isName(namedAction)) {
+          if (namedAction instanceof Name) {
             resultObj.action = namedAction.name;
           }
           break;
@@ -1587,7 +1588,7 @@ class Catalog {
       resultObj.unsafeUrl = url;
     }
     if (dest) {
-      if (isName(dest)) {
+      if (dest instanceof Name) {
         dest = dest.name;
       }
       if (isString(dest) || Array.isArray(dest)) {
diff --git a/src/core/ccitt_stream.js b/src/core/ccitt_stream.js
index d716b4841..0e3b1cea3 100644
--- a/src/core/ccitt_stream.js
+++ b/src/core/ccitt_stream.js
@@ -13,9 +13,9 @@
  * limitations under the License.
  */
 
-import { Dict, isDict } from "./primitives.js";
 import { CCITTFaxDecoder } from "./ccitt.js";
 import { DecodeStream } from "./decode_stream.js";
+import { Dict } from "./primitives.js";
 
 class CCITTFaxStream extends DecodeStream {
   constructor(str, maybeLength, params) {
@@ -24,7 +24,7 @@ class CCITTFaxStream extends DecodeStream {
     this.str = str;
     this.dict = str.dict;
 
-    if (!isDict(params)) {
+    if (!(params instanceof Dict)) {
       params = Dict.empty;
     }
 
diff --git a/src/core/cmap.js b/src/core/cmap.js
index 9c0c373ff..2316608ca 100644
--- a/src/core/cmap.js
+++ b/src/core/cmap.js
@@ -20,7 +20,7 @@ import {
   unreachable,
   warn,
 } from "../shared/util.js";
-import { EOF, isCmd, isName } from "./primitives.js";
+import { Cmd, EOF, isCmd, Name } from "./primitives.js";
 import { BaseStream } from "./base_stream.js";
 import { Lexer } from "./parser.js";
 import { MissingDataException } from "./core_utils.js";
@@ -901,7 +901,7 @@ const CMapFactory = (function CMapFactoryClosure() {
 
   function parseCMapName(cMap, lexer) {
     const obj = lexer.getObj();
-    if (isName(obj) && isString(obj.name)) {
+    if (obj instanceof Name && isString(obj.name)) {
       cMap.name = obj.name;
     }
   }
@@ -913,19 +913,19 @@ const CMapFactory = (function CMapFactoryClosure() {
         const obj = lexer.getObj();
         if (obj === EOF) {
           break;
-        } else if (isName(obj)) {
+        } else if (obj instanceof Name) {
           if (obj.name === "WMode") {
             parseWMode(cMap, lexer);
           } else if (obj.name === "CMapName") {
             parseCMapName(cMap, lexer);
           }
           previous = obj;
-        } else if (isCmd(obj)) {
+        } else if (obj instanceof Cmd) {
           switch (obj.cmd) {
             case "endcmap":
               break objLoop;
             case "usecmap":
-              if (isName(previous)) {
+              if (previous instanceof Name) {
                 embeddedUseCMap = previous.name;
               }
               break;
@@ -1024,7 +1024,7 @@ const CMapFactory = (function CMapFactoryClosure() {
       const fetchBuiltInCMap = params.fetchBuiltInCMap;
       const useCMap = params.useCMap;
 
-      if (isName(encoding)) {
+      if (encoding instanceof Name) {
         return createBuiltInCMap(encoding.name, fetchBuiltInCMap);
       } else if (encoding instanceof BaseStream) {
         const parsedCMap = await parseCMap(
diff --git a/src/core/colorspace.js b/src/core/colorspace.js
index 5dc8fc681..145498461 100644
--- a/src/core/colorspace.js
+++ b/src/core/colorspace.js
@@ -21,7 +21,7 @@ import {
   unreachable,
   warn,
 } from "../shared/util.js";
-import { isDict, isName, Name, Ref } from "./primitives.js";
+import { Dict, Name, Ref } from "./primitives.js";
 import { BaseStream } from "./base_stream.js";
 import { MissingDataException } from "./core_utils.js";
 
@@ -378,7 +378,7 @@ class ColorSpace {
    */
   static _parse(cs, xref, resources = null, pdfFunctionFactory) {
     cs = xref.fetchIfRef(cs);
-    if (isName(cs)) {
+    if (cs instanceof Name) {
       switch (cs.name) {
         case "G":
         case "DeviceGray":
@@ -392,12 +392,12 @@ class ColorSpace {
         case "Pattern":
           return new PatternCS(/* baseCS = */ null);
         default:
-          if (isDict(resources)) {
+          if (resources instanceof Dict) {
             const colorSpaces = resources.get("ColorSpace");
-            if (isDict(colorSpaces)) {
+            if (colorSpaces instanceof Dict) {
               const resourcesCS = colorSpaces.get(cs.name);
               if (resourcesCS) {
-                if (isName(resourcesCS)) {
+                if (resourcesCS instanceof Name) {
                   return this._parse(
                     resourcesCS,
                     xref,
diff --git a/src/core/crypto.js b/src/core/crypto.js
index d76b6f483..4aeddae95 100644
--- a/src/core/crypto.js
+++ b/src/core/crypto.js
@@ -24,7 +24,7 @@ import {
   utf8StringToString,
   warn,
 } from "../shared/util.js";
-import { isDict, isName, Name } from "./primitives.js";
+import { Dict, isName, Name } from "./primitives.js";
 import { DecryptStream } from "./decrypt_stream.js";
 
 class ARCFourCipher {
@@ -1647,7 +1647,7 @@ const CipherTransformFactory = (function CipherTransformFactoryClosure() {
   }
 
   function buildCipherConstructor(cf, name, num, gen, key) {
-    if (!isName(name)) {
+    if (!(name instanceof Name)) {
       throw new FormatError("Invalid crypt filter name.");
     }
     const cryptFilter = cf.get(name.name);
@@ -1713,7 +1713,7 @@ const CipherTransformFactory = (function CipherTransformFactoryClosure() {
           // Trying to find default handler -- it usually has Length.
           const cfDict = dict.get("CF");
           const streamCryptoName = dict.get("StmF");
-          if (isDict(cfDict) && isName(streamCryptoName)) {
+          if (cfDict instanceof Dict && streamCryptoName instanceof Name) {
             cfDict.suppressEncryption = true; // See comment below.
             const handlerDict = cfDict.get(streamCryptoName.name);
             keyLength = (handlerDict && handlerDict.get("Length")) || 128;
@@ -1838,7 +1838,7 @@ const CipherTransformFactory = (function CipherTransformFactoryClosure() {
 
       if (algorithm >= 4) {
         const cf = dict.get("CF");
-        if (isDict(cf)) {
+        if (cf instanceof Dict) {
           // The 'CF' dictionary itself should not be encrypted, and by setting
           // `suppressEncryption` we can prevent an infinite loop inside of
           // `XRef_fetchUncompressed` if the dictionary contains indirect
diff --git a/src/core/document.js b/src/core/document.js
index a11b75365..bcef7d875 100644
--- a/src/core/document.js
+++ b/src/core/document.js
@@ -44,7 +44,7 @@ import {
   XRefEntryException,
   XRefParseException,
 } from "./core_utils.js";
-import { Dict, isDict, isName, Name, Ref } from "./primitives.js";
+import { Dict, isName, Name, Ref } from "./primitives.js";
 import { getXfaFontDict, getXfaFontName } from "./xfa_fonts.js";
 import { NullStream, Stream } from "./stream.js";
 import { AnnotationFactory } from "./annotation.js";
@@ -120,7 +120,7 @@ class Page {
     if (!Array.isArray(value)) {
       return value;
     }
-    if (value.length === 1 || !isDict(value[0])) {
+    if (value.length === 1 || !(value[0] instanceof Dict)) {
       return value[0];
     }
     return Dict.merge({ xref: this.xref, dictArray: value });
@@ -1175,7 +1175,7 @@ class PDFDocument {
       info("The document information dictionary is invalid.");
     }
 
-    if (isDict(infoDict)) {
+    if (infoDict instanceof Dict) {
       // Fill the document info with valid entries from the specification,
       // as well as any existing well-formed custom entries.
       for (const key of infoDict.getKeys()) {
@@ -1196,7 +1196,7 @@ class PDFDocument {
           let customValue;
           if (isString(value)) {
             customValue = stringToPDFString(value);
-          } else if (isName(value) || isNum(value) || isBool(value)) {
+          } else if (value instanceof Name || isNum(value) || isBool(value)) {
             customValue = value;
           } else {
             info(`Unsupported value in document info for (custom) "${key}".`);
diff --git a/src/core/evaluator.js b/src/core/evaluator.js
index 47bc38133..6b8b907b5 100644
--- a/src/core/evaluator.js
+++ b/src/core/evaluator.js
@@ -35,16 +35,7 @@ import {
   warn,
 } from "../shared/util.js";
 import { CMapFactory, IdentityCMap } from "./cmap.js";
-import {
-  Cmd,
-  Dict,
-  EOF,
-  isDict,
-  isName,
-  Name,
-  Ref,
-  RefSet,
-} from "./primitives.js";
+import { Cmd, Dict, EOF, isName, Name, Ref, RefSet } from "./primitives.js";
 import { ErrorFont, Font } from "./fonts.js";
 import { FontFlags, getFontType } from "./fonts_utils.js";
 import {
@@ -133,7 +124,7 @@ function normalizeBlendMode(value, parsingArray = false) {
     return "source-over";
   }
 
-  if (!isName(value)) {
+  if (!(value instanceof Name)) {
     if (parsingArray) {
       return null;
     }
@@ -1042,7 +1033,7 @@ class PartialEvaluator {
             gStateObj.push([key, false]);
             break;
           }
-          if (isDict(value)) {
+          if (value instanceof Dict) {
             isSimpleGState = false;
 
             promise = promise.then(() => {
@@ -1162,7 +1153,7 @@ class PartialEvaluator {
     }
 
     font = xref.fetchIfRef(fontRef);
-    if (!isDict(font)) {
+    if (!(font instanceof Dict)) {
       return errorFont();
     }
 
@@ -1190,7 +1181,7 @@ class PartialEvaluator {
       fontID = `f${fontRef.toString()}`;
     }
 
-    if (hash && isDict(descriptor)) {
+    if (hash && descriptor instanceof Dict) {
       if (!descriptor.fontAliases) {
         descriptor.fontAliases = Object.create(null);
       }
@@ -1459,7 +1450,7 @@ class PartialEvaluator {
     }
     const length = array.length;
     const operator = this.xref.fetchIfRef(array[0]);
-    if (length < 2 || !isName(operator)) {
+    if (length < 2 || !(operator instanceof Name)) {
       warn("Invalid visibility expression");
       return;
     }
@@ -1490,10 +1481,10 @@ class PartialEvaluator {
 
   async parseMarkedContentProps(contentProperties, resources) {
     let optionalContent;
-    if (isName(contentProperties)) {
+    if (contentProperties instanceof Name) {
       const properties = resources.get("Properties");
       optionalContent = properties.get(contentProperties.name);
-    } else if (isDict(contentProperties)) {
+    } else if (contentProperties instanceof Dict) {
       optionalContent = contentProperties;
     } else {
       throw new FormatError("Optional content properties malformed.");
@@ -1521,7 +1512,7 @@ class PartialEvaluator {
       const optionalContentGroups = optionalContent.get("OCGs");
       if (
         Array.isArray(optionalContentGroups) ||
-        isDict(optionalContentGroups)
+        optionalContentGroups instanceof Dict
       ) {
         const groupIds = [];
         if (Array.isArray(optionalContentGroups)) {
@@ -1536,9 +1527,10 @@ class PartialEvaluator {
         return {
           type: optionalContentType,
           ids: groupIds,
-          policy: isName(optionalContent.get("P"))
-            ? optionalContent.get("P").name
-            : null,
+          policy:
+            optionalContent.get("P") instanceof Name
+              ? optionalContent.get("P").name
+              : null,
           expression: null,
         };
       } else if (optionalContentGroups instanceof Ref) {
@@ -1667,7 +1659,7 @@ class PartialEvaluator {
                 }
 
                 const type = xobj.dict.get("Subtype");
-                if (!isName(type)) {
+                if (!(type instanceof Name)) {
                   throw new FormatError("XObject should have a Name subtype");
                 }
 
@@ -2067,7 +2059,7 @@ class PartialEvaluator {
             // but doing so is meaningless without knowing the semantics.
             continue;
           case OPS.beginMarkedContentProps:
-            if (!isName(args[0])) {
+            if (!(args[0] instanceof Name)) {
               warn(`Expected name for beginMarkedContentProps arg0=${args[0]}`);
               continue;
             }
@@ -2989,7 +2981,7 @@ class PartialEvaluator {
                 }
 
                 const type = xobj.dict.get("Subtype");
-                if (!isName(type)) {
+                if (!(type instanceof Name)) {
                   throw new FormatError("XObject should have a Name subtype");
                 }
 
@@ -3125,7 +3117,7 @@ class PartialEvaluator {
             if (includeMarkedContent) {
               textContent.items.push({
                 type: "beginMarkedContent",
-                tag: isName(args[0]) ? args[0].name : null,
+                tag: args[0] instanceof Name ? args[0].name : null,
               });
             }
             break;
@@ -3133,7 +3125,7 @@ class PartialEvaluator {
             if (includeMarkedContent) {
               flushTextContentItem();
               let mcid = null;
-              if (isDict(args[1])) {
+              if (args[1] instanceof Dict) {
                 mcid = args[1].get("MCID");
               }
               textContent.items.push({
@@ -3141,7 +3133,7 @@ class PartialEvaluator {
                 id: Number.isInteger(mcid)
                   ? `${self.idFactory.getPageObjId()}_mcid${mcid}`
                   : null,
-                tag: isName(args[0]) ? args[0].name : null,
+                tag: args[0] instanceof Name ? args[0].name : null,
               });
             }
             break;
@@ -3197,7 +3189,7 @@ class PartialEvaluator {
     if (properties.composite) {
       // CIDSystemInfo helps to match CID to glyphs
       const cidSystemInfo = dict.get("CIDSystemInfo");
-      if (isDict(cidSystemInfo)) {
+      if (cidSystemInfo instanceof Dict) {
         properties.cidSystemInfo = {
           registry: stringToPDFString(cidSystemInfo.get("Registry")),
           ordering: stringToPDFString(cidSystemInfo.get("Ordering")),
@@ -3222,11 +3214,10 @@ class PartialEvaluator {
     let encoding;
     if (dict.has("Encoding")) {
       encoding = dict.get("Encoding");
-      if (isDict(encoding)) {
+      if (encoding instanceof Dict) {
         baseEncodingName = encoding.get("BaseEncoding");
-        baseEncodingName = isName(baseEncodingName)
-          ? baseEncodingName.name
-          : null;
+        baseEncodingName =
+          baseEncodingName instanceof Name ? baseEncodingName.name : null;
         // Load the differences between the base and original
         if (encoding.has("Differences")) {
           const diffEncoding = encoding.get("Differences");
@@ -3235,7 +3226,7 @@ class PartialEvaluator {
             const data = xref.fetchIfRef(diffEncoding[j]);
             if (isNum(data)) {
               index = data;
-            } else if (isName(data)) {
+            } else if (data instanceof Name) {
               differences[index++] = data.name;
             } else {
               throw new FormatError(
@@ -3244,7 +3235,7 @@ class PartialEvaluator {
             }
           }
         }
-      } else if (isName(encoding)) {
+      } else if (encoding instanceof Name) {
         baseEncodingName = encoding.name;
       } else {
         throw new FormatError("Encoding is not a Name nor a Dict");
@@ -3496,7 +3487,7 @@ class PartialEvaluator {
     if (!cmapObj) {
       return Promise.resolve(null);
     }
-    if (isName(cmapObj)) {
+    if (cmapObj instanceof Name) {
       return CMapFactory.create({
         encoding: cmapObj,
         fetchBuiltInCMap: this._fetchBuiltInCMapBound,
@@ -3648,7 +3639,7 @@ class PartialEvaluator {
       } else {
         // Trying get the BaseFont metrics (see comment above).
         const baseFontName = dict.get("BaseFont");
-        if (isName(baseFontName)) {
+        if (baseFontName instanceof Name) {
           const metrics = this.getBaseFontMetrics(baseFontName.name);
 
           glyphsWidths = this.buildCharCodeToWidth(metrics.widths, properties);
@@ -3746,7 +3737,7 @@ class PartialEvaluator {
   preEvaluateFont(dict) {
     const baseDict = dict;
     let type = dict.get("Subtype");
-    if (!isName(type)) {
+    if (!(type instanceof Name)) {
       throw new FormatError("invalid font Subtype");
     }
 
@@ -3767,7 +3758,7 @@ class PartialEvaluator {
         throw new FormatError("Descendant font is not a dictionary.");
       }
       type = dict.get("Subtype");
-      if (!isName(type)) {
+      if (!(type instanceof Name)) {
         throw new FormatError("invalid font Subtype");
       }
       composite = true;
@@ -3780,13 +3771,13 @@ class PartialEvaluator {
       hash = new MurmurHash3_64();
 
       const encoding = baseDict.getRaw("Encoding");
-      if (isName(encoding)) {
+      if (encoding instanceof Name) {
         hash.update(encoding.name);
       } else if (encoding instanceof Ref) {
         hash.update(encoding.toString());
-      } else if (isDict(encoding)) {
+      } else if (encoding instanceof Dict) {
         for (const entry of encoding.getRawValues()) {
-          if (isName(entry)) {
+          if (entry instanceof Name) {
             hash.update(entry.name);
           } else if (entry instanceof Ref) {
             hash.update(entry.toString());
@@ -3797,7 +3788,7 @@ class PartialEvaluator {
 
             for (let j = 0; j < diffLength; j++) {
               const diffEntry = entry[j];
-              if (isName(diffEntry)) {
+              if (diffEntry instanceof Name) {
                 diffBuf[j] = diffEntry.name;
               } else if (isNum(diffEntry) || diffEntry instanceof Ref) {
                 diffBuf[j] = diffEntry.toString();
@@ -3821,7 +3812,7 @@ class PartialEvaluator {
               stream.end - stream.start
             );
         hash.update(uint8array);
-      } else if (isName(toUnicode)) {
+      } else if (toUnicode instanceof Name) {
         hash.update(toUnicode.name);
       }
 
@@ -3909,7 +3900,7 @@ class PartialEvaluator {
         // FontDescriptor was not required.
         // This case is here for compatibility.
         let baseFontName = dict.get("BaseFont");
-        if (!isName(baseFontName)) {
+        if (!(baseFontName instanceof Name)) {
           throw new FormatError("Base font is not specified");
         }
 
@@ -4005,7 +3996,7 @@ class PartialEvaluator {
     }
     fontName = fontName || baseFont;
 
-    if (!isName(fontName)) {
+    if (!(fontName instanceof Name)) {
       throw new FormatError("invalid font name");
     }
 
@@ -4089,7 +4080,7 @@ class PartialEvaluator {
 
     if (composite) {
       const cidEncoding = baseDict.get("Encoding");
-      if (isName(cidEncoding)) {
+      if (cidEncoding instanceof Name) {
         properties.cidEncoding = cidEncoding.name;
       }
       const cMap = await CMapFactory.create({
diff --git a/src/core/file_spec.js b/src/core/file_spec.js
index 5d0dda9f4..3eb1c5a7d 100644
--- a/src/core/file_spec.js
+++ b/src/core/file_spec.js
@@ -15,7 +15,7 @@
 
 import { stringToPDFString, warn } from "../shared/util.js";
 import { BaseStream } from "./base_stream.js";
-import { isDict } from "./primitives.js";
+import { Dict } from "./primitives.js";
 
 function pickPlatformItem(dict) {
   // Look for the filename in this order:
@@ -43,7 +43,7 @@ function pickPlatformItem(dict) {
  */
 class FileSpec {
   constructor(root, xref) {
-    if (!root || !isDict(root)) {
+    if (!(root instanceof Dict)) {
       return;
     }
     this.xref = xref;
diff --git a/src/core/function.js b/src/core/function.js
index 05a2e317d..d402d067b 100644
--- a/src/core/function.js
+++ b/src/core/function.js
@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-import { Dict, isDict, Ref } from "./primitives.js";
+import { Dict, Ref } from "./primitives.js";
 import {
   FormatError,
   info,
@@ -508,7 +508,7 @@ function isPDFFunction(v) {
   let fnDict;
   if (typeof v !== "object") {
     return false;
-  } else if (isDict(v)) {
+  } else if (v instanceof Dict) {
     fnDict = v;
   } else if (v instanceof BaseStream) {
     fnDict = v.dict;
diff --git a/src/core/image.js b/src/core/image.js
index 850967185..322903b58 100644
--- a/src/core/image.js
+++ b/src/core/image.js
@@ -14,12 +14,12 @@
  */
 
 import { assert, FormatError, ImageKind, info, warn } from "../shared/util.js";
-import { isName, Name } from "./primitives.js";
 import { BaseStream } from "./base_stream.js";
 import { ColorSpace } from "./colorspace.js";
 import { DecodeStream } from "./decode_stream.js";
 import { JpegStream } from "./jpeg_stream.js";
 import { JpxImage } from "./jpx.js";
+import { Name } from "./primitives.js";
 
 /**
  * Decode and clamp a value. The formula is different from the spec because we
@@ -95,7 +95,7 @@ class PDFImage {
     const dict = image.dict;
 
     const filter = dict.get("F", "Filter");
-    if (isName(filter)) {
+    if (filter instanceof Name) {
       switch (filter.name) {
         case "JPXDecode":
           const jpxImage = new JpxImage();
diff --git a/src/core/jbig2_stream.js b/src/core/jbig2_stream.js
index a83d6a9b1..bbea4c539 100644
--- a/src/core/jbig2_stream.js
+++ b/src/core/jbig2_stream.js
@@ -15,7 +15,7 @@
 
 import { BaseStream } from "./base_stream.js";
 import { DecodeStream } from "./decode_stream.js";
-import { isDict } from "./primitives.js";
+import { Dict } from "./primitives.js";
 import { Jbig2Image } from "./jbig2.js";
 import { shadow } from "../shared/util.js";
 
@@ -50,7 +50,7 @@ class Jbig2Stream extends DecodeStream {
     const jbig2Image = new Jbig2Image();
 
     const chunks = [];
-    if (isDict(this.params)) {
+    if (this.params instanceof Dict) {
       const globalsStream = this.params.get("JBIG2Globals");
       if (globalsStream instanceof BaseStream) {
         const globals = globalsStream.getBytes();
diff --git a/src/core/jpeg_stream.js b/src/core/jpeg_stream.js
index 7cd822ec7..11bdf5e43 100644
--- a/src/core/jpeg_stream.js
+++ b/src/core/jpeg_stream.js
@@ -14,7 +14,7 @@
  */
 
 import { DecodeStream } from "./decode_stream.js";
-import { isDict } from "./primitives.js";
+import { Dict } from "./primitives.js";
 import { JpegImage } from "./jpg.js";
 import { shadow } from "../shared/util.js";
 
@@ -81,7 +81,7 @@ class JpegStream extends DecodeStream {
       }
     }
     // Fetching the 'ColorTransform' entry, if it exists.
-    if (isDict(this.params)) {
+    if (this.params instanceof Dict) {
       const colorTransform = this.params.get("ColorTransform");
       if (Number.isInteger(colorTransform)) {
         jpegOptions.colorTransform = colorTransform;
diff --git a/src/core/name_number_tree.js b/src/core/name_number_tree.js
index e0bf13ec8..96089841c 100644
--- a/src/core/name_number_tree.js
+++ b/src/core/name_number_tree.js
@@ -13,8 +13,8 @@
  * limitations under the License.
  */
 
+import { Dict, RefSet } from "./primitives.js";
 import { FormatError, unreachable, warn } from "../shared/util.js";
-import { isDict, RefSet } from "./primitives.js";
 
 /**
  * A NameTree/NumberTree is like a Dict but has some advantageous properties,
@@ -43,7 +43,7 @@ class NameOrNumberTree {
     const queue = [this.root];
     while (queue.length > 0) {
       const obj = xref.fetchIfRef(queue.shift());
-      if (!isDict(obj)) {
+      if (!(obj instanceof Dict)) {
         continue;
       }
       if (obj.has("Kids")) {
diff --git a/src/core/parser.js b/src/core/parser.js
index 7eae17afa..e3267783d 100644
--- a/src/core/parser.js
+++ b/src/core/parser.js
@@ -22,16 +22,7 @@ import {
   StreamType,
   warn,
 } from "../shared/util.js";
-import {
-  Cmd,
-  Dict,
-  EOF,
-  isCmd,
-  isDict,
-  isName,
-  Name,
-  Ref,
-} from "./primitives.js";
+import { Cmd, Dict, EOF, isCmd, Name, Ref } from "./primitives.js";
 import {
   isWhiteSpace,
   MissingDataException,
@@ -137,7 +128,7 @@ class Parser {
         case "<<": // dictionary or stream
           const dict = new Dict(this.xref);
           while (!isCmd(this.buf1, ">>") && this.buf1 !== EOF) {
-            if (!isName(this.buf1)) {
+            if (!(this.buf1 instanceof Name)) {
               info("Malformed dictionary: key must be a name object");
               this.shift();
               continue;
@@ -498,7 +489,7 @@ class Parser {
     const dict = new Dict(this.xref);
     let dictLength;
     while (!isCmd(this.buf1, "ID") && this.buf1 !== EOF) {
-      if (!isName(this.buf1)) {
+      if (!(this.buf1 instanceof Name)) {
         throw new FormatError("Dictionary key must be a name object");
       }
       const key = this.buf1.name;
@@ -515,11 +506,11 @@ class Parser {
     // Extract the name of the first (i.e. the current) image filter.
     const filter = dict.get("F", "Filter");
     let filterName;
-    if (isName(filter)) {
+    if (filter instanceof Name) {
       filterName = filter.name;
     } else if (Array.isArray(filter)) {
       const filterZero = this.xref.fetchIfRef(filter[0]);
-      if (isName(filterZero)) {
+      if (filterZero instanceof Name) {
         filterName = filterZero.name;
       }
     }
@@ -704,7 +695,7 @@ class Parser {
     let filter = dict.get("F", "Filter");
     let params = dict.get("DP", "DecodeParms");
 
-    if (isName(filter)) {
+    if (filter instanceof Name) {
       if (Array.isArray(params)) {
         warn("/DecodeParms should not be an Array, when /Filter is a Name.");
       }
@@ -717,7 +708,7 @@ class Parser {
       const paramsArray = params;
       for (let i = 0, ii = filterArray.length; i < ii; ++i) {
         filter = this.xref.fetchIfRef(filterArray[i]);
-        if (!isName(filter)) {
+        if (!(filter instanceof Name)) {
           throw new FormatError(`Bad filter name "${filter}"`);
         }
 
@@ -1401,7 +1392,7 @@ class Linearization {
         Number.isInteger(obj1) &&
         Number.isInteger(obj2) &&
         isCmd(obj3, "obj") &&
-        isDict(linDict) &&
+        linDict instanceof Dict &&
         isNum((obj = linDict.get("Linearized"))) &&
         obj > 0
       )
diff --git a/src/core/predictor_stream.js b/src/core/predictor_stream.js
index afeec2adb..e36920a11 100644
--- a/src/core/predictor_stream.js
+++ b/src/core/predictor_stream.js
@@ -14,14 +14,14 @@
  */
 
 import { DecodeStream } from "./decode_stream.js";
+import { Dict } from "./primitives.js";
 import { FormatError } from "../shared/util.js";
-import { isDict } from "./primitives.js";
 
 class PredictorStream extends DecodeStream {
   constructor(str, maybeLength, params) {
     super(maybeLength);
 
-    if (!isDict(params)) {
+    if (!(params instanceof Dict)) {
       return str; // no prediction
     }
     const predictor = (this.predictor = params.get("Predictor") || 1);
diff --git a/src/core/struct_tree.js b/src/core/struct_tree.js
index e91124f5e..740ab4499 100644
--- a/src/core/struct_tree.js
+++ b/src/core/struct_tree.js
@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-import { isDict, isName, Ref } from "./primitives.js";
+import { Dict, isName, Name, Ref } from "./primitives.js";
 import { isString, stringToPDFString, warn } from "../shared/util.js";
 import { NumberTree } from "./name_number_tree.js";
 
@@ -38,11 +38,11 @@ class StructTreeRoot {
 
   readRoleMap() {
     const roleMapDict = this.dict.get("RoleMap");
-    if (!isDict(roleMapDict)) {
+    if (!(roleMapDict instanceof Dict)) {
       return;
     }
     roleMapDict.forEach((key, value) => {
-      if (!isName(value)) {
+      if (!(value instanceof Name)) {
         return;
       }
       this.roleMap.set(key, value.name);
@@ -64,7 +64,7 @@ class StructElementNode {
 
   get role() {
     const nameObj = this.dict.get("S");
-    const name = isName(nameObj) ? nameObj.name : "";
+    const name = nameObj instanceof Name ? nameObj.name : "";
     const { root } = this.tree;
     if (root.roleMap.has(name)) {
       return root.roleMap.get(name);
@@ -112,7 +112,7 @@ class StructElementNode {
     let kidDict = null;
     if (kid instanceof Ref) {
       kidDict = this.dict.xref.fetch(kid);
-    } else if (isDict(kid)) {
+    } else if (kid instanceof Dict) {
       kidDict = kid;
     }
     if (!kidDict) {
@@ -123,7 +123,8 @@ class StructElementNode {
       pageObjId = pageRef.toString();
     }
 
-    const type = isName(kidDict.get("Type")) ? kidDict.get("Type").name : null;
+    const type =
+      kidDict.get("Type") instanceof Name ? kidDict.get("Type").name : null;
     if (type === "MCR") {
       if (this.tree.pageDict.objId !== pageObjId) {
         return null;
@@ -256,7 +257,7 @@ class StructTreePage {
       return false;
     }
 
-    if (isDict(obj)) {
+    if (obj instanceof Dict) {
       if (obj.objId !== dict.objId) {
         return false;
       }
diff --git a/src/core/writer.js b/src/core/writer.js
index 9985f7bb1..5d525c961 100644
--- a/src/core/writer.js
+++ b/src/core/writer.js
@@ -14,7 +14,7 @@
  */
 
 import { bytesToString, escapeString, warn } from "../shared/util.js";
-import { Dict, isDict, isName, Name, Ref } from "./primitives.js";
+import { Dict, Name, Ref } from "./primitives.js";
 import { escapePDFName, parseXFAPath } from "./core_utils.js";
 import { SimpleDOMNode, SimpleXMLParser } from "./xml_parser.js";
 import { BaseStream } from "./base_stream.js";
@@ -71,7 +71,7 @@ function numberToString(value) {
 }
 
 function writeValue(value, buffer, transform) {
-  if (isName(value)) {
+  if (value instanceof Name) {
     buffer.push(`/${escapePDFName(value.name)}`);
   } else if (value instanceof Ref) {
     buffer.push(`${value.num} ${value.gen} R`);
@@ -86,7 +86,7 @@ function writeValue(value, buffer, transform) {
     buffer.push(numberToString(value));
   } else if (typeof value === "boolean") {
     buffer.push(value.toString());
-  } else if (isDict(value)) {
+  } else if (value instanceof Dict) {
     writeDict(value, buffer, transform);
   } else if (value instanceof BaseStream) {
     writeStream(value, buffer, transform);
diff --git a/test/unit/primitives_spec.js b/test/unit/primitives_spec.js
index fbcdaa62f..e2fb10edb 100644
--- a/test/unit/primitives_spec.js
+++ b/test/unit/primitives_spec.js
@@ -470,6 +470,8 @@ describe("primitives", function () {
   });
 
   describe("isName", function () {
+    /* eslint-disable no-restricted-syntax */
+
     it("handles non-names", function () {
       const nonName = {};
       expect(isName(nonName)).toEqual(false);
@@ -493,9 +495,13 @@ describe("primitives", function () {
       expect(isName(emptyName, "")).toEqual(true);
       expect(isName(emptyName, "string")).toEqual(false);
     });
+
+    /* eslint-enable no-restricted-syntax */
   });
 
   describe("isCmd", function () {
+    /* eslint-disable no-restricted-syntax */
+
     it("handles non-commands", function () {
       const nonCmd = {};
       expect(isCmd(nonCmd)).toEqual(false);
@@ -511,9 +517,13 @@ describe("primitives", function () {
       expect(isCmd(cmd, "BT")).toEqual(true);
       expect(isCmd(cmd, "ET")).toEqual(false);
     });
+
+    /* eslint-enable no-restricted-syntax */
   });
 
   describe("isDict", function () {
+    /* eslint-disable no-restricted-syntax */
+
     it("handles non-dictionaries", function () {
       const nonDict = {};
       expect(isDict(nonDict)).toEqual(false);
@@ -531,6 +541,8 @@ describe("primitives", function () {
       expect(isDict(dict, "Page")).toEqual(true);
       expect(isDict(dict, "Contents")).toEqual(false);
     });
+
+    /* eslint-enable no-restricted-syntax */
   });
 
   describe("isRefsEqual", function () {