diff --git a/packages/workbox-build/package.json b/packages/workbox-build/package.json
index 6a0517624..b5ee1d925 100644
--- a/packages/workbox-build/package.json
+++ b/packages/workbox-build/package.json
@@ -38,7 +38,6 @@
     "rollup": "^2.43.1",
     "rollup-plugin-terser": "^7.0.0",
     "source-map": "^0.8.0-beta.0",
-    "source-map-url": "^0.4.0",
     "stringify-object": "^3.3.0",
     "strip-comments": "^2.0.1",
     "tempy": "^0.6.0",
diff --git a/packages/workbox-build/src/inject-manifest.ts b/packages/workbox-build/src/inject-manifest.ts
index 3a88e1b85..8c1a14a81 100644
--- a/packages/workbox-build/src/inject-manifest.ts
+++ b/packages/workbox-build/src/inject-manifest.ts
@@ -9,7 +9,6 @@
 import {RawSourceMap} from 'source-map';
 import assert from 'assert';
 import fse from 'fs-extra';
-import sourceMapURL from 'source-map-url';
 import stringify from 'fast-json-stable-stringify';
 import upath from 'upath';
 
@@ -17,6 +16,7 @@ import {BuildResult} from './types';
 import {errors} from './lib/errors';
 import {escapeRegExp} from './lib/escape-regexp';
 import {getFileManifestEntries} from './lib/get-file-manifest-entries';
+import {getSourceMapURL} from './lib/get-source-map-url';
 import {rebasePath} from './lib/rebase-path';
 import {replaceAndUpdateSourceMap} from './lib/replace-and-update-source-map';
 import {translateURLToSourcemapPaths} from './lib/translate-url-to-sourcemap-paths';
@@ -164,7 +164,7 @@ export async function injectManifest(config: unknown): Promise<BuildResult> {
   const manifestString = stringify(manifestEntries);
   const filesToWrite: {[key: string]: string} = {};
 
-  const url = sourceMapURL.getFrom(swFileContents) as string; // eslint-disable-line
+  const url = getSourceMapURL(swFileContents);
   // See https://github.com/GoogleChrome/workbox/issues/2957
   const {destPath, srcPath, warning} = translateURLToSourcemapPaths(
     url,
diff --git a/packages/workbox-build/src/lib/get-source-map-url.ts b/packages/workbox-build/src/lib/get-source-map-url.ts
new file mode 100644
index 000000000..6b0aee97b
--- /dev/null
+++ b/packages/workbox-build/src/lib/get-source-map-url.ts
@@ -0,0 +1,32 @@
+/*
+  Copyright 2022 Google LLC
+
+  Use of this source code is governed by an MIT-style
+  license that can be found in the LICENSE file or at
+  https://opensource.org/licenses/MIT.
+*/
+
+// Adapted from https://github.com/lydell/source-map-url/blob/master/source-map-url.js
+// See https://github.com/GoogleChrome/workbox/issues/3019
+const innerRegex = /[#@] sourceMappingURL=([^\s'"]*)/;
+const regex = RegExp(
+  '(?:' +
+    '/\\*' +
+    '(?:\\s*\r?\n(?://)?)?' +
+    '(?:' +
+    innerRegex.source +
+    ')' +
+    '\\s*' +
+    '\\*/' +
+    '|' +
+    '//(?:' +
+    innerRegex.source +
+    ')' +
+    ')' +
+    '\\s*',
+);
+
+export function getSourceMapURL(srcContents: string): string | null {
+  const match = srcContents.match(regex);
+  return match ? match[1] || match[2] || '' : null;
+}
diff --git a/packages/workbox-build/src/lib/translate-url-to-sourcemap-paths.ts b/packages/workbox-build/src/lib/translate-url-to-sourcemap-paths.ts
index ec5d37945..072eac40d 100644
--- a/packages/workbox-build/src/lib/translate-url-to-sourcemap-paths.ts
+++ b/packages/workbox-build/src/lib/translate-url-to-sourcemap-paths.ts
@@ -12,7 +12,7 @@ import upath from 'upath';
 import {errors} from './errors';
 
 export function translateURLToSourcemapPaths(
-  url: string,
+  url: string | null,
   swSrc: string,
   swDest: string,
 ): {
diff --git a/packages/workbox-build/src/source-map-url.d.ts b/packages/workbox-build/src/source-map-url.d.ts
deleted file mode 100644
index 8958463c8..000000000
--- a/packages/workbox-build/src/source-map-url.d.ts
+++ /dev/null
@@ -1 +0,0 @@
-declare module 'source-map-url';
diff --git a/packages/workbox-webpack-plugin/package.json b/packages/workbox-webpack-plugin/package.json
index 3cc307770..b5a1f0fe9 100644
--- a/packages/workbox-webpack-plugin/package.json
+++ b/packages/workbox-webpack-plugin/package.json
@@ -23,7 +23,6 @@
   "dependencies": {
     "fast-json-stable-stringify": "^2.1.0",
     "pretty-bytes": "^5.4.1",
-    "source-map-url": "^0.4.0",
     "upath": "^1.2.0",
     "webpack-sources": "^1.4.3",
     "workbox-build": "6.4.2"
diff --git a/packages/workbox-webpack-plugin/src/lib/get-sourcemap-asset-name.ts b/packages/workbox-webpack-plugin/src/lib/get-sourcemap-asset-name.ts
index 2c59d2aff..2a5e9006d 100644
--- a/packages/workbox-webpack-plugin/src/lib/get-sourcemap-asset-name.ts
+++ b/packages/workbox-webpack-plugin/src/lib/get-sourcemap-asset-name.ts
@@ -6,7 +6,7 @@
   https://opensource.org/licenses/MIT.
 */
 
-import sourceMapURL from 'source-map-url';
+import {getSourceMapURL} from 'workbox-build/build/lib/get-source-map-url';
 import upath from 'upath';
 import type {Compilation} from 'webpack';
 
@@ -33,8 +33,7 @@ export function getSourcemapAssetName(
   swContents: string,
   swDest: string,
 ): string | undefined {
-  // eslint-disable-next-line
-  const url = sourceMapURL.getFrom(swContents);
+  const url = getSourceMapURL(swContents);
   if (url) {
     // Translate the relative URL to what the presumed name for the webpack
     // asset should be.
diff --git a/packages/workbox-webpack-plugin/src/source-map-url.d.ts b/packages/workbox-webpack-plugin/src/source-map-url.d.ts
deleted file mode 100644
index 8958463c8..000000000
--- a/packages/workbox-webpack-plugin/src/source-map-url.d.ts
+++ /dev/null
@@ -1 +0,0 @@
-declare module 'source-map-url';