diff --git a/lib/generate.js b/lib/generate.js
deleted file mode 100644
index 6405336..0000000
--- a/lib/generate.js
+++ /dev/null
@@ -1,65 +0,0 @@
-'use strict';
-
-var css = require('css');
-var acorn = require('acorn');
-var SourceMapGenerator = require('source-map').SourceMapGenerator;
-
-function generateJs(sourcePath, fileContent) {
-  var generator = new SourceMapGenerator({ file: sourcePath });
-  var tokenizer = acorn.tokenizer(fileContent, { locations: true });
-
-  while (true) {
-    var token = tokenizer.getToken();
-
-    if (token.type.label === 'eof') {
-      break;
-    }
-    var mapping = {
-      original: token.loc.start,
-      generated: token.loc.start,
-      source: sourcePath
-    };
-    if (token.type.label === 'name') {
-      mapping.name = token.value;
-    }
-    generator.addMapping(mapping);
-  }
-  generator.setSourceContent(sourcePath, fileContent);
-
-  return generator.toJSON();
-}
-
-function generateCss(sourcePath, fileContent) {
-  var generator = new SourceMapGenerator({ file: sourcePath });
-  var ast = css.parse(fileContent, { silent: true });
-
-  function registerTokens(ast) {
-    if (ast.position) {
-      generator.addMapping({
-        original: ast.position.start,
-        generated: ast.position.start,
-        source: sourcePath
-      });
-    }
-
-    for (var key in ast) {
-      if (key === 'position' || !ast[key]) {
-        break;
-      }
-        if (Object.prototype.toString.call(ast[key]) === '[object Object]') {
-          registerTokens(ast[key]);
-        } else if (Array.isArray(ast[key])) {
-          ast[key].forEach(registerTokens);
-        }
-    }
-  }
-  registerTokens(ast);
-  generator.setSourceContent(sourcePath, fileContent);
-
-  return generator.toJSON();
-}
-
-module.exports = {
-  js: generateJs,
-  css: generateCss,
-};
diff --git a/lib/helpers.js b/lib/helpers.js
index 9adb79f..ac6b4ad 100644
--- a/lib/helpers.js
+++ b/lib/helpers.js
@@ -9,8 +9,6 @@ var convert = require('convert-source-map');
 var stripBom = require('strip-bom');
 var detectNewline = require('detect-newline');
 
-var generate = require('./generate');
-
 var urlRegex = /^(https?|webpack(-[^:]+)?):\/\//;
 
 function isRemoteSource(source) {
@@ -134,19 +132,6 @@ function fixImportedSourceMap(file, state, options, callback) {
 
 function mapsLoaded(file, state, options, callback) {
 
-  if (!state.map && options.identityMap) {
-    var sourcePath = unixStylePath(file.relative);
-
-    switch (file.extname) {
-      case '.js':
-        state.map = generate.js(sourcePath, state.content);
-        break;
-      case '.css':
-        state.map = generate.css(sourcePath, state.content);
-        break;
-    }
-  }
-
   if (!state.map) {
     state.map = {
       version: 3,
diff --git a/package.json b/package.json
index 45e374c..4a23148 100644
--- a/package.json
+++ b/package.json
@@ -22,14 +22,11 @@
     "vinyl-fs": "^2.4.3"
   },
   "dependencies": {
-    "acorn": "^4.0.3",
     "async": "^2.1.4",
     "convert-source-map": "1.3.0",
-    "css": "^2.2.1",
     "detect-newline": "^2.1.0",
     "graceful-fs": "^4.1.6",
     "object.defaults": "^1.0.0",
-    "source-map": "^0.5.6",
     "strip-bom": "^2.0.0",
     "through2": "^2.0.1",
     "vinyl": "^1.2.0"
diff --git a/test/add.js b/test/add.js
index 304e6b3..aab6efa 100644
--- a/test/add.js
+++ b/test/add.js
@@ -165,34 +165,6 @@ describe('add', function() {
 		});
 	});
 
-	it('should add a valid source if wished', function(done) {
-		sourcemaps.add(makeFile(), { identityMap: true }, function(err, data) {
-			expect(data).toExist();
-			expect(data).toExist();
-			expect(data.sourceMap).toExist();
-			expect(String(data.sourceMap.version)).toBe('3');
-			expect(data.sourceMap.sources[0]).toBe('helloworld.js');
-			expect(data.sourceMap.sourcesContent[0]).toBe(sourceContent);
-			expect(data.sourceMap.names).toEqual(['helloWorld', 'console','log']);
-			expect(data.sourceMap.mappings).toBe('AAAA,YAAY;;AAEZ,SAASA,UAAU,CAAC,EAAE;CACrBC,OAAO,CAACC,GAAG,CAAC,cAAc,CAAC;AAC5B');
-			done(err);
-		});
-	});
-
-	it('should add a valid source map for CSS if wished', function(done) {
-		sourcemaps.add(makeFileCSS(), { identityMap: true }, function(err, data) {
-			expect(data).toExist();
-			expect(data instanceof File).toExist();
-			expect(data.sourceMap).toExist();
-			expect(String(data.sourceMap.version)).toBe('3');
-			expect(data.sourceMap.sources[0]).toBe('test.css');
-			expect(data.sourceMap.sourcesContent[0]).toBe(sourceContentCSS);
-			expect(data.sourceMap.names).toEqual([]);
-			expect(data.sourceMap.mappings).toBe('CAAC;EACC;EACA');
-			done(err);
-		});
-	});
-
 	it('should import an existing inline source map', function(done) {
 		sourcemaps.add(makeFileWithInlineSourceMap(), { loadMaps: true }, function(err, data) {
 			expect(data).toExist();