diff --git a/src/core/catalog.js b/src/core/catalog.js
index 044979a9f..920cc26ba 100644
--- a/src/core/catalog.js
+++ b/src/core/catalog.js
@@ -13,19 +13,6 @@
  * limitations under the License.
  */
 
-import {
-  clearPrimitiveCaches,
-  Dict,
-  isDict,
-  isName,
-  isRef,
-  isRefsEqual,
-  isStream,
-  Name,
-  Ref,
-  RefSet,
-  RefSetCache,
-} from "./primitives.js";
 import {
   collectActions,
   MissingDataException,
@@ -48,8 +35,21 @@ import {
   stringToUTF8String,
   warn,
 } from "../shared/util.js";
+import {
+  Dict,
+  isDict,
+  isName,
+  isRef,
+  isRefsEqual,
+  isStream,
+  Name,
+  Ref,
+  RefSet,
+  RefSetCache,
+} from "./primitives.js";
 import { NameTree, NumberTree } from "./name_number_tree.js";
 import { BaseStream } from "./base_stream.js";
+import { clearGlobalCaches } from "./cleanup_helper.js";
 import { ColorSpace } from "./colorspace.js";
 import { FileSpec } from "./file_spec.js";
 import { GlobalImageCache } from "./image_utils.js";
@@ -1069,7 +1069,7 @@ class Catalog {
   }
 
   cleanup(manuallyTriggered = false) {
-    clearPrimitiveCaches();
+    clearGlobalCaches();
     this.globalImageCache.clear(/* onlyData = */ manuallyTriggered);
     this.pageKidsCountCache.clear();
     this.pageIndexCache.clear();
diff --git a/src/core/cleanup_helper.js b/src/core/cleanup_helper.js
new file mode 100644
index 000000000..f014519bd
--- /dev/null
+++ b/src/core/cleanup_helper.js
@@ -0,0 +1,24 @@
+/* Copyright 2022 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { clearPrimitiveCaches } from "./primitives.js";
+import { clearUnicodeCaches } from "./unicode.js";
+
+function clearGlobalCaches() {
+  clearPrimitiveCaches();
+  clearUnicodeCaches();
+}
+
+export { clearGlobalCaches };
diff --git a/src/core/document.js b/src/core/document.js
index 8d113abf8..19d2e66b4 100644
--- a/src/core/document.js
+++ b/src/core/document.js
@@ -35,16 +35,6 @@ import {
   Util,
   warn,
 } from "../shared/util.js";
-import {
-  clearPrimitiveCaches,
-  Dict,
-  isDict,
-  isName,
-  isRef,
-  isStream,
-  Name,
-  Ref,
-} from "./primitives.js";
 import {
   collectActions,
   getInheritableProperty,
@@ -54,12 +44,22 @@ import {
   XRefEntryException,
   XRefParseException,
 } from "./core_utils.js";
+import {
+  Dict,
+  isDict,
+  isName,
+  isRef,
+  isStream,
+  Name,
+  Ref,
+} from "./primitives.js";
 import { getXfaFontDict, getXfaFontName } from "./xfa_fonts.js";
 import { NullStream, Stream } from "./stream.js";
 import { AnnotationFactory } from "./annotation.js";
 import { BaseStream } from "./base_stream.js";
 import { calculateMD5 } from "./crypto.js";
 import { Catalog } from "./catalog.js";
+import { clearGlobalCaches } from "./cleanup_helper.js";
 import { Linearization } from "./parser.js";
 import { ObjectLoader } from "./object_loader.js";
 import { OperatorList } from "./operator_list.js";
@@ -1449,7 +1449,7 @@ class PDFDocument {
   async cleanup(manuallyTriggered = false) {
     return this.catalog
       ? this.catalog.cleanup(manuallyTriggered)
-      : clearPrimitiveCaches();
+      : clearGlobalCaches();
   }
 
   /**
diff --git a/src/core/unicode.js b/src/core/unicode.js
index 647272834..6116fab6d 100644
--- a/src/core/unicode.js
+++ b/src/core/unicode.js
@@ -1641,16 +1641,29 @@ function reverseIfRtl(chars) {
 }
 
 const SpecialCharRegExp = new RegExp("^(\\s)|(\\p{Mn})|(\\p{Cf})$", "u");
+const CategoryCache = new Map();
+
 function getCharUnicodeCategory(char) {
+  const cachedCategory = CategoryCache.get(char);
+  if (cachedCategory) {
+    return cachedCategory;
+  }
   const groups = char.match(SpecialCharRegExp);
-  return {
+  const category = {
     isWhitespace: !!(groups && groups[1]),
     isZeroWidthDiacritic: !!(groups && groups[2]),
     isInvisibleFormatMark: !!(groups && groups[3]),
   };
+  CategoryCache.set(char, category);
+  return category;
+}
+
+function clearUnicodeCaches() {
+  CategoryCache.clear();
 }
 
 export {
+  clearUnicodeCaches,
   getCharUnicodeCategory,
   getNormalizedUnicodes,
   getUnicodeForGlyph,
diff --git a/src/core/worker.js b/src/core/worker.js
index 24694c0a8..328ffb7f2 100644
--- a/src/core/worker.js
+++ b/src/core/worker.js
@@ -32,8 +32,9 @@ import {
   VerbosityLevel,
   warn,
 } from "../shared/util.js";
-import { clearPrimitiveCaches, Dict, Ref } from "./primitives.js";
+import { Dict, Ref } from "./primitives.js";
 import { LocalPdfManager, NetworkPdfManager } from "./pdf_manager.js";
+import { clearGlobalCaches } from "./cleanup_helper.js";
 import { incrementalUpdate } from "./writer.js";
 import { isNodeJS } from "../shared/is_node.js";
 import { MessageHandler } from "../shared/message_handler.js";
@@ -795,7 +796,7 @@ class WorkerMessageHandler {
 
         pdfManager = null;
       } else {
-        clearPrimitiveCaches();
+        clearGlobalCaches();
       }
       if (cancelXHRs) {
         cancelXHRs(new AbortException("Worker was terminated."));