diff --git a/lib/source-map-url.js b/lib/source-map-url.js
new file mode 100644
index 0000000..b1aa641
--- /dev/null
+++ b/lib/source-map-url.js
@@ -0,0 +1,47 @@
+// Copyright 2014 Simon Lydell
+// X11 (“MIT”) Licensed. (See LICENSE.)
+// copied from https://github.com/lydell/source-map-url/blob/4106e5f0b001918790e3b830d2541252ba025a3d/source-map-url.js
+// adapted to remove umd
+/* eslint-disable no-var */
+
+var innerRegex = /[#@] sourceMappingURL=([^\s'"]*)/
+
+var regex = RegExp(
+  "(?:" +
+    "/\\*" +
+    "(?:\\s*\r?\n(?://)?)?" +
+    "(?:" + innerRegex.source + ")" +
+    "\\s*" +
+    "\\*/" +
+    "|" +
+    "//(?:" + innerRegex.source + ")" +
+  ")" +
+  "\\s*"
+)
+
+module.exports = {
+  regex: regex,
+  _innerRegex: innerRegex,
+
+  getFrom: function(code) {
+    var match = code.match(regex)
+    return (match ? match[1] || match[2] || "" : null)
+  },
+
+  existsIn: function(code) {
+    return regex.test(code)
+  },
+
+  removeFrom: function(code) {
+    return code.replace(regex, "")
+  },
+
+  insertBefore: function(code, string) {
+    var match = code.match(regex)
+    if (match) {
+      return code.slice(0, match.index) + string + code.slice(match.index)
+    } else {
+      return code + string
+    }
+  }
+}
\ No newline at end of file
diff --git a/lib/source-map.js b/lib/source-map.js
index effd931..d5bc0fd 100644
--- a/lib/source-map.js
+++ b/lib/source-map.js
@@ -1,7 +1,7 @@
 'use strict';
 
 const fs = require('fs-extra');
-const srcURL = require('source-map-url');
+const srcURL = require('./source-map-url');
 const path = require('path');
 const MemoryStreams = require('memory-streams');
 const Coder = require('./coder');
diff --git a/package.json b/package.json
index d56e9c2..d4a0434 100644
--- a/package.json
+++ b/package.json
@@ -19,8 +19,7 @@
     "heimdalljs-logger": "^0.1.9",
     "memory-streams": "^0.1.3",
     "mkdirp": "^0.5.0",
-    "@jacobq/source-map": "^1.1.0",
-    "source-map-url": "^0.3.0"
+    "@jacobq/source-map": "^1.1.0"
   },
   "devDependencies": {
     "chai": "^4.1.2",
diff --git a/test/source-map-url.js b/test/source-map-url.js
new file mode 100644
index 0000000..f5b1ce0
--- /dev/null
+++ b/test/source-map-url.js
@@ -0,0 +1,405 @@
+// Copyright 2014 Simon Lydell
+// X11 (“MIT”) Licensed. (See LICENSE.)
+// copied from https://github.com/lydell/source-map-url/blob/4106e5f0b001918790e3b830d2541252ba025a3d/test/source-map-url.js
+
+/* eslint-disable */
+
+var { expect } = require('chai');
+
+var sourceMappingURL = require("../lib/source-map-url")
+
+var comments = {
+
+  universal: [
+    "/*# sourceMappingURL=foo.js.map */"
+  ],
+
+  js: [
+    "//# sourceMappingURL=foo.js.map"
+  ],
+
+  block: [
+    "/*",
+    "# sourceMappingURL=foo.js.map",
+    "*/"
+  ],
+
+  mix: [
+    "/*",
+    "//# sourceMappingURL=foo.js.map",
+    "*/"
+  ]
+
+}
+
+var nonTrailingComments = {
+
+  jsLeading: {
+    contents: [
+      "//# sourceMappingURL=foo.js.map",
+      "(function(){})"
+    ],
+    solution: [
+      "(function(){})"
+    ]
+  },
+
+  mixEmbedded: {
+    contents: [
+      "/*! Library Name v1.0.0",
+      "//# sourceMappingURL=foo.js.map",
+      "*/",
+      "(function(){})"
+    ],
+    solution: [
+      "/*! Library Name v1.0.0",
+      "*/",
+      "(function(){})"
+    ]
+  }
+
+}
+
+function forEachComment(fn) {
+  forOf(comments, function(name, comment) {
+    var description = "the '" + name + "' syntax with "
+    fn(comment.join("\n"),   description + "regular newlines")
+    fn(comment.join("\r\n"), description + "Windows newlines")
+  })
+}
+
+function forEachNonTrailingComment(fn) {
+  forOf(nonTrailingComments, function(name, comment) {
+
+    var description = "the '" + name + "' syntax with "
+
+    fn({
+      contents: comment.contents.join("\n"),
+      solution: comment.solution.join("\n")
+    }, description + "regular newlines")
+
+    fn({
+      contents: comment.contents.join("\r\n"),
+      solution: comment.solution.join("\r\n")
+    }, description + "Windows newlines")
+  })
+}
+
+function forOf(obj, fn) {
+  for (var key in obj) {
+    if (Object.prototype.hasOwnProperty.call(obj, key)) {
+      fn(key, obj[key])
+    }
+  }
+}
+
+
+describe("sourceMappingURL", function() {
+
+  describe(".getFrom", function() {
+
+    forEachComment(function(comment, description) {
+
+      it("gets the url from " + description, function() {
+        expect(sourceMappingURL.getFrom("code\n" + comment))
+          .to.equal("foo.js.map")
+
+        expect(sourceMappingURL.getFrom("code" + comment))
+          .to.equal("foo.js.map")
+
+        expect(sourceMappingURL.getFrom(comment))
+          .to.equal("foo.js.map")
+      })
+
+    })
+
+    forEachNonTrailingComment(function(comment, description) {
+
+      it("gets the url from " + description, function() {
+        expect(sourceMappingURL.getFrom("code\n" + comment.contents))
+          .to.equal("foo.js.map")
+
+        expect(sourceMappingURL.getFrom("code" + comment.contents))
+          .to.equal("foo.js.map")
+
+        expect(sourceMappingURL.getFrom(comment.contents))
+          .to.equal("foo.js.map")
+      })
+
+    })
+
+
+    it("returns null if no comment", function() {
+      expect(sourceMappingURL.getFrom("code"))
+        .to.equal(null)
+    })
+
+
+    it("can return an empty string as url", function() {
+      expect(sourceMappingURL.getFrom("/*# sourceMappingURL= */"))
+        .to.equal("")
+    })
+
+
+    it("is detachable", function() {
+      var get = sourceMappingURL.getFrom
+      expect(get("/*# sourceMappingURL=foo */"))
+        .to.equal("foo")
+    })
+
+  })
+
+
+  describe(".existsIn", function() {
+
+    forEachComment(function(comment, description) {
+
+      it("returns true for " + description, function() {
+        expect(sourceMappingURL.existsIn("code\n" + comment))
+          .to.equal(true)
+
+        expect(sourceMappingURL.existsIn("code" + comment))
+          .to.equal(true)
+
+        expect(sourceMappingURL.existsIn(comment))
+          .to.equal(true)
+      })
+
+    })
+
+    forEachNonTrailingComment(function(comment, description) {
+
+      it("returns true for " + description, function() {
+        expect(sourceMappingURL.existsIn("code\n" + comment.contents))
+          .to.equal(true)
+
+        expect(sourceMappingURL.existsIn("code" + comment.contents))
+          .to.equal(true)
+
+        expect(sourceMappingURL.existsIn(comment.contents))
+          .to.equal(true)
+      })
+
+    })
+
+
+    it("returns false if no comment", function() {
+      expect(sourceMappingURL.existsIn("code"))
+        .to.equal(false)
+    })
+
+
+    it("is detachable", function() {
+      var has = sourceMappingURL.existsIn
+      expect(has("/*# sourceMappingURL=foo */"))
+        .to.equal(true)
+    })
+
+  })
+
+
+  describe(".removeFrom", function() {
+
+    forEachComment(function(comment, description) {
+
+      it("removes the comment for " + description, function() {
+        expect(sourceMappingURL.removeFrom("code\n" + comment))
+          .to.equal("code\n")
+
+        expect(sourceMappingURL.removeFrom("code" + comment))
+          .to.equal("code")
+
+        expect(sourceMappingURL.removeFrom(comment))
+          .to.equal("")
+      })
+
+    })
+
+    forEachNonTrailingComment(function(comment, description) {
+
+      it("removes the comment for " + description, function() {
+        expect(sourceMappingURL.removeFrom("code\n" + comment.contents))
+          .to.equal("code\n" + comment.solution)
+
+        expect(sourceMappingURL.removeFrom("code" + comment.contents))
+          .to.equal("code" + comment.solution)
+
+        expect(sourceMappingURL.removeFrom(comment.contents))
+          .to.equal(comment.solution)
+      })
+
+    })
+
+
+    it("does nothing if no comment", function() {
+      expect(sourceMappingURL.removeFrom("code\n"))
+        .to.equal("code\n")
+    })
+
+
+    it("is detachable", function() {
+      var remove = sourceMappingURL.removeFrom
+      expect(remove("/*# sourceMappingURL=foo */"))
+        .to.equal("")
+    })
+
+  })
+
+
+  describe(".insertBefore", function() {
+
+    forEachComment(function(comment, description) {
+
+      it("inserts a string before the comment for " + description, function() {
+        expect(sourceMappingURL.insertBefore("code\n" + comment, "more code\n"))
+          .to.equal("code\nmore code\n" + comment)
+
+        expect(sourceMappingURL.insertBefore("code" + comment, "\nmore code"))
+          .to.equal("code\nmore code" + comment)
+
+        expect(sourceMappingURL.insertBefore(comment, "some code"))
+          .to.equal("some code" + comment)
+      })
+
+    })
+
+
+    it("inserts a string before an embedded comment", function() {
+      expect(sourceMappingURL.insertBefore("/*! Library Name v1.0.0\n" +
+        "//# sourceMappingURL=foo.js.map\n*/\n(function(){})", "code\n"))
+        .to.equal("/*! Library Name v1.0.0\ncode\n" +
+          "//# sourceMappingURL=foo.js.map\n*/\n(function(){})")
+    })
+
+
+    it("inserts a string before a leading comment", function() {
+      expect(sourceMappingURL.insertBefore("//# sourceMappingURL=foo.js.map\n" +
+        "(function(){})", "code\n"))
+        .to.equal("code\n//# sourceMappingURL=foo.js.map\n" +
+          "(function(){})")
+    })
+
+
+    it("appends if no comment", function() {
+      expect(sourceMappingURL.insertBefore("code", "\nmore code"))
+        .to.equal("code\nmore code")
+    })
+
+
+    it("is detachable", function() {
+      var insertBefore = sourceMappingURL.insertBefore
+      expect(insertBefore("/*# sourceMappingURL=foo */", "bar"))
+        .to.equal("bar/*# sourceMappingURL=foo */")
+    })
+
+  })
+
+
+  describe(".regex", function() {
+
+    it("includes ._innerRegex", function() {
+      expect(sourceMappingURL.regex.source)
+        .to.contain(sourceMappingURL._innerRegex.source)
+    })
+
+
+    var match = function(code) {
+      expect(code)
+        .to.match(sourceMappingURL.regex)
+    }
+
+    var noMatch = function(code) {
+      expect(code)
+        .not.to.match(sourceMappingURL.regex)
+    }
+
+
+    forEachComment(function(comment, description) {
+
+      it("matches " + description, function() {
+        match("code\n" + comment)
+        match("code" + comment)
+        match(comment)
+      })
+
+
+      it("matches " + description + ", with trailing whitespace", function() {
+        match(comment + "  ")
+        match(comment + "\n")
+        match(comment + "\n\n\t\n    \t  ")
+      })
+
+    })
+
+
+    it("does not match some cases that are easy to mess up", function() {
+      noMatch(
+        "/* # sourceMappingURL=foo */"
+      )
+
+      noMatch(
+        "// # sourceMappingURL=foo"
+      )
+    })
+
+
+    it("is liberal regarding inner whitespace", function() {
+      match(
+        "/*# sourceMappingURL=foo*/"
+      )
+
+      match(
+        "/*# sourceMappingURL=foo    */"
+      )
+
+      match(
+        "/*# sourceMappingURL=foo   \t\n" +
+        "*/"
+      )
+
+      match(
+        "/*    \n" +
+        "# sourceMappingURL=foo\n" +
+        "*/"
+      )
+
+      match(
+        "/*\n" +
+        "# sourceMappingURL=foo\n" +
+        "     */"
+      )
+
+      match(
+        "/*\n" +
+        "# sourceMappingURL=foo\n" +
+        "\n" +
+        "\t\n" +
+        "*/"
+      )
+    })
+
+  })
+
+
+  describe("._innerRegex", function() {
+
+    it("matches the contents of sourceMappingURL comments", function() {
+      expect("# sourceMappingURL=http://www.example.com/foo/bar.js.map")
+        .to.match(sourceMappingURL._innerRegex)
+    })
+
+
+    it("captures the url in the first capture group", function() {
+      expect(sourceMappingURL._innerRegex.exec("# sourceMappingURL=foo")[1])
+        .to.equal("foo")
+    })
+
+
+    it("supports the legacy syntax", function() {
+      expect("@ sourceMappingURL=http://www.example.com/foo/bar.js.map")
+        .to.match(sourceMappingURL._innerRegex)
+    })
+
+  })
+
+})
\ No newline at end of file
diff --git a/yarn.lock b/yarn.lock
index 1e123e9..6f83657 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1103,11 +1103,6 @@ slice-ansi@1.0.0:
   dependencies:
     is-fullwidth-code-point "^2.0.0"
 
-source-map-url@^0.3.0:
-  version "0.3.0"
-  resolved "https://registry.npmjs.org/source-map-url/-/source-map-url-0.3.0.tgz"
-  integrity sha1-fsrxO1e80J2opAxdJp2zN5nUqvk=
-
 sprintf-js@~1.0.2:
   version "1.0.3"
   resolved "https://registry.npmjs.org/sprintf-js/-/sprintf-js-1.0.3.tgz"