diff --git a/test/unit/clitests.json b/test/unit/clitests.json
index 99cca1b41..8dd259caf 100644
--- a/test/unit/clitests.json
+++ b/test/unit/clitests.json
@@ -24,6 +24,7 @@
     "encodings_spec.js",
     "evaluator_spec.js",
     "event_utils_spec.js",
+    "font_substitutions_spec.js",
     "function_spec.js",
     "message_handler_spec.js",
     "metadata_spec.js",
diff --git a/test/unit/font_substitutions_spec.js b/test/unit/font_substitutions_spec.js
new file mode 100644
index 000000000..798feaa3f
--- /dev/null
+++ b/test/unit/font_substitutions_spec.js
@@ -0,0 +1,351 @@
+/* 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 { createIdFactory } from "./test_utils.js";
+import { getFontSubstitution } from "../../src/core/font_substitutions.js";
+
+describe("getFontSubstitution", function () {
+  const idFactory = createIdFactory(0);
+  const localFontPath = "/tmp/";
+
+  it("should substitute an unknown font", () => {
+    const fontName = "Foo";
+    const fontSubstitution = getFontSubstitution(
+      new Map(),
+      idFactory,
+      localFontPath,
+      fontName,
+      undefined
+    );
+    expect(fontSubstitution).toEqual(
+      jasmine.objectContaining({
+        guessFallback: true,
+        src: "local(Foo)",
+        style: {
+          style: "normal",
+          weight: "normal",
+        },
+      })
+    );
+  });
+
+  it("should substitute an unknown bold font", () => {
+    const fontName = "Foo-Bold";
+    const fontSubstitution = getFontSubstitution(
+      new Map(),
+      idFactory,
+      localFontPath,
+      fontName,
+      undefined
+    );
+    expect(fontSubstitution).toEqual(
+      jasmine.objectContaining({
+        guessFallback: true,
+        src: "local(Foo-Bold)",
+        style: {
+          style: "normal",
+          weight: "bold",
+        },
+      })
+    );
+  });
+
+  it("should substitute an unknown italic font", () => {
+    const fontName = "Foo-Italic";
+    const fontSubstitution = getFontSubstitution(
+      new Map(),
+      idFactory,
+      localFontPath,
+      fontName,
+      undefined
+    );
+    expect(fontSubstitution).toEqual(
+      jasmine.objectContaining({
+        guessFallback: true,
+        src: "local(Foo-Italic)",
+        style: {
+          style: "italic",
+          weight: "normal",
+        },
+      })
+    );
+  });
+
+  it("should substitute an unknown bold italic font", () => {
+    const fontName = "Foo-BoldItalic";
+    const fontSubstitution = getFontSubstitution(
+      new Map(),
+      idFactory,
+      localFontPath,
+      fontName,
+      undefined
+    );
+    expect(fontSubstitution).toEqual(
+      jasmine.objectContaining({
+        guessFallback: true,
+        src: "local(Foo-BoldItalic)",
+        style: {
+          style: "italic",
+          weight: "bold",
+        },
+      })
+    );
+  });
+
+  it("should substitute an unknown font but with a standard font", () => {
+    const fontName = "Foo";
+    const fontSubstitution = getFontSubstitution(
+      new Map(),
+      idFactory,
+      localFontPath,
+      fontName,
+      "Helvetica"
+    );
+    expect(fontSubstitution).toEqual(
+      jasmine.objectContaining({
+        guessFallback: false,
+        src:
+          "local(Foo),local(Helvetica),local(Helvetica Neue)," +
+          "local(Arial),local(Arial Nova),local(Liberation Sans)," +
+          "local(Arimo),local(Nimbus Sans),local(Nimbus Sans L)," +
+          "local(A030),local(TeX Gyre Heros),local(FreeSans)," +
+          "local(DejaVu Sans),local(Albany),local(Bitstream Vera Sans)," +
+          "local(Arial Unicode MS),local(Microsoft Sans Serif)," +
+          "local(Apple Symbols),local(Cantarell)," +
+          "url(/tmp/LiberationSans-Regular.ttf)",
+        style: {
+          style: "normal",
+          weight: "normal",
+        },
+      })
+    );
+  });
+
+  it("should substitute an unknown font but with a standard italic font", () => {
+    const fontName = "Foo-Italic";
+    const fontSubstitution = getFontSubstitution(
+      new Map(),
+      idFactory,
+      localFontPath,
+      fontName,
+      "Helvetica-Oblique"
+    );
+    expect(fontSubstitution).toEqual(
+      jasmine.objectContaining({
+        guessFallback: false,
+        src:
+          "local(Foo-Italic),local(Helvetica Italic)," +
+          "local(Helvetica Neue Italic),local(Arial Italic)," +
+          "local(Arial Nova Italic),local(Liberation Sans Italic)," +
+          "local(Arimo Italic),local(Nimbus Sans Italic)," +
+          "local(Nimbus Sans L Italic),local(A030 Italic)," +
+          "local(TeX Gyre Heros Italic),local(FreeSans Italic)," +
+          "local(DejaVu Sans Italic),local(Albany Italic)," +
+          "local(Bitstream Vera Sans Italic),local(Arial Unicode MS Italic)," +
+          "local(Microsoft Sans Serif Italic),local(Apple Symbols Italic)," +
+          "local(Cantarell Italic),url(/tmp/LiberationSans-Italic.ttf)",
+        style: {
+          style: "italic",
+          weight: "normal",
+        },
+      })
+    );
+  });
+
+  it("should substitute an unknown font but with a standard bold font", () => {
+    const fontName = "Foo-Bold";
+    const fontSubstitution = getFontSubstitution(
+      new Map(),
+      idFactory,
+      localFontPath,
+      fontName,
+      "Helvetica-Bold"
+    );
+    expect(fontSubstitution).toEqual(
+      jasmine.objectContaining({
+        guessFallback: false,
+        src:
+          "local(Foo-Bold),local(Helvetica Bold),local(Helvetica Neue Bold)," +
+          "local(Arial Bold),local(Arial Nova Bold)," +
+          "local(Liberation Sans Bold),local(Arimo Bold)," +
+          "local(Nimbus Sans Bold),local(Nimbus Sans L Bold)," +
+          "local(A030 Bold),local(TeX Gyre Heros Bold),local(FreeSans Bold)," +
+          "local(DejaVu Sans Bold),local(Albany Bold)," +
+          "local(Bitstream Vera Sans Bold),local(Arial Unicode MS Bold)," +
+          "local(Microsoft Sans Serif Bold),local(Apple Symbols Bold)," +
+          "local(Cantarell Bold),url(/tmp/LiberationSans-Bold.ttf)",
+        style: {
+          style: "normal",
+          weight: "bold",
+        },
+      })
+    );
+  });
+
+  it("should substitute an unknown font but with a standard bold italic font", () => {
+    const fontName = "Foo-BoldItalic";
+    const fontSubstitution = getFontSubstitution(
+      new Map(),
+      idFactory,
+      localFontPath,
+      fontName,
+      "Helvetica-BoldOblique"
+    );
+    expect(fontSubstitution).toEqual(
+      jasmine.objectContaining({
+        guessFallback: false,
+        src:
+          "local(Foo-BoldItalic),local(Helvetica Bold Italic)," +
+          "local(Helvetica Neue Bold Italic),local(Arial Bold Italic)," +
+          "local(Arial Nova Bold Italic),local(Liberation Sans Bold Italic)," +
+          "local(Arimo Bold Italic),local(Nimbus Sans Bold Italic)," +
+          "local(Nimbus Sans L Bold Italic),local(A030 Bold Italic)," +
+          "local(TeX Gyre Heros Bold Italic),local(FreeSans Bold Italic)," +
+          "local(DejaVu Sans Bold Italic),local(Albany Bold Italic)," +
+          "local(Bitstream Vera Sans Bold Italic)," +
+          "local(Arial Unicode MS Bold Italic)," +
+          "local(Microsoft Sans Serif Bold Italic)," +
+          "local(Apple Symbols Bold Italic),local(Cantarell Bold Italic)," +
+          "url(/tmp/LiberationSans-BoldItalic.ttf)",
+        style: {
+          style: "italic",
+          weight: "bold",
+        },
+      })
+    );
+  });
+
+  it("should substitute Calibri", () => {
+    const fontName = "Calibri";
+    const fontSubstitution = getFontSubstitution(
+      new Map(),
+      idFactory,
+      localFontPath,
+      fontName,
+      undefined
+    );
+    expect(fontSubstitution).toEqual(
+      jasmine.objectContaining({
+        guessFallback: false,
+        src:
+          "local(Calibri),local(Carlito),local(Helvetica)," +
+          "local(Helvetica Neue),local(Arial),local(Arial Nova)," +
+          "local(Liberation Sans),local(Arimo),local(Nimbus Sans)," +
+          "local(Nimbus Sans L),local(A030),local(TeX Gyre Heros)," +
+          "local(FreeSans),local(DejaVu Sans),local(Albany)," +
+          "local(Bitstream Vera Sans),local(Arial Unicode MS)," +
+          "local(Microsoft Sans Serif),local(Apple Symbols)," +
+          "local(Cantarell),url(/tmp/LiberationSans-Regular.ttf)",
+        style: {
+          style: "normal",
+          weight: "normal",
+        },
+      })
+    );
+  });
+
+  it("should substitute Calibri-Bold", () => {
+    const fontName = "Calibri-Bold";
+    const fontSubstitution = getFontSubstitution(
+      new Map(),
+      idFactory,
+      localFontPath,
+      fontName,
+      undefined
+    );
+    expect(fontSubstitution).toEqual(
+      jasmine.objectContaining({
+        guessFallback: false,
+        src:
+          "local(Calibri Bold),local(Carlito Bold),local(Helvetica Bold)," +
+          "local(Helvetica Neue Bold),local(Arial Bold)," +
+          "local(Arial Nova Bold),local(Liberation Sans Bold)," +
+          "local(Arimo Bold),local(Nimbus Sans Bold)," +
+          "local(Nimbus Sans L Bold),local(A030 Bold)," +
+          "local(TeX Gyre Heros Bold),local(FreeSans Bold)," +
+          "local(DejaVu Sans Bold),local(Albany Bold)," +
+          "local(Bitstream Vera Sans Bold),local(Arial Unicode MS Bold)," +
+          "local(Microsoft Sans Serif Bold),local(Apple Symbols Bold)," +
+          "local(Cantarell Bold),url(/tmp/LiberationSans-Bold.ttf)",
+        style: {
+          style: "normal",
+          weight: "bold",
+        },
+      })
+    );
+  });
+
+  it("should substitute Arial Black", () => {
+    const fontName = "Arial Black";
+    const fontSubstitution = getFontSubstitution(
+      new Map(),
+      idFactory,
+      localFontPath,
+      fontName,
+      undefined
+    );
+    expect(fontSubstitution).toEqual(
+      jasmine.objectContaining({
+        guessFallback: false,
+        src:
+          "local(Arial Black),local(Helvetica Bold)," +
+          "local(Helvetica Neue Bold),local(Arial Bold)," +
+          "local(Arial Nova Bold),local(Liberation Sans Bold)," +
+          "local(Arimo Bold),local(Nimbus Sans Bold)," +
+          "local(Nimbus Sans L Bold),local(A030 Bold)," +
+          "local(TeX Gyre Heros Bold),local(FreeSans Bold)," +
+          "local(DejaVu Sans Bold),local(Albany Bold)," +
+          "local(Bitstream Vera Sans Bold),local(Arial Unicode MS Bold)," +
+          "local(Microsoft Sans Serif Bold),local(Apple Symbols Bold)," +
+          "local(Cantarell Bold),url(/tmp/LiberationSans-Bold.ttf)",
+        style: {
+          style: "normal",
+          weight: "900",
+        },
+      })
+    );
+  });
+
+  it("should substitute Arial Black Bold", () => {
+    const fontName = "Arial-Black-Bold";
+    const fontSubstitution = getFontSubstitution(
+      new Map(),
+      idFactory,
+      localFontPath,
+      fontName,
+      undefined
+    );
+    expect(fontSubstitution).toEqual(
+      jasmine.objectContaining({
+        guessFallback: false,
+        src:
+          "local(Arial Black),local(Helvetica Bold)," +
+          "local(Helvetica Neue Bold),local(Arial Bold)," +
+          "local(Arial Nova Bold),local(Liberation Sans Bold)," +
+          "local(Arimo Bold),local(Nimbus Sans Bold)," +
+          "local(Nimbus Sans L Bold),local(A030 Bold)," +
+          "local(TeX Gyre Heros Bold),local(FreeSans Bold)," +
+          "local(DejaVu Sans Bold),local(Albany Bold)," +
+          "local(Bitstream Vera Sans Bold),local(Arial Unicode MS Bold)," +
+          "local(Microsoft Sans Serif Bold),local(Apple Symbols Bold)," +
+          "local(Cantarell Bold),url(/tmp/LiberationSans-Bold.ttf)",
+        style: {
+          style: "normal",
+          weight: "900",
+        },
+      })
+    );
+  });
+});
diff --git a/test/unit/jasmine-boot.js b/test/unit/jasmine-boot.js
index 56cb1adfc..42a2ba6ca 100644
--- a/test/unit/jasmine-boot.js
+++ b/test/unit/jasmine-boot.js
@@ -67,6 +67,7 @@ async function initializePDFJS(callback) {
       "pdfjs-test/unit/event_utils_spec.js",
       "pdfjs-test/unit/function_spec.js",
       "pdfjs-test/unit/fetch_stream_spec.js",
+      "pdfjs-test/unit/font_substitutions_spec.js",
       "pdfjs-test/unit/message_handler_spec.js",
       "pdfjs-test/unit/metadata_spec.js",
       "pdfjs-test/unit/murmurhash3_spec.js",