diff --git a/packages/metro-bundler/src/ModuleGraph/worker/__tests__/transform-module-test.js b/packages/metro-bundler/src/ModuleGraph/worker/__tests__/transform-module-test.js
index ae8d3b19..22b1bb58 100644
--- a/packages/metro-bundler/src/ModuleGraph/worker/__tests__/transform-module-test.js
+++ b/packages/metro-bundler/src/ModuleGraph/worker/__tests__/transform-module-test.js
@@ -162,9 +162,11 @@ describe('transforming JS modules:', () => {
   it('creates source maps', done => {
     transformModule(sourceCode, options(), (error, result) => {
       const {code, map} = result.details.transformed.default;
-      const column = code.indexOf('code');
+      const position = findColumnAndLine(code, 'code');
+      expect(position).not.toBeNull();
+
       const consumer = new SourceMapConsumer(map);
-      expect(consumer.originalPositionFor({line: 1, column})).toEqual(
+      expect(consumer.originalPositionFor(position)).toEqual(
         expect.objectContaining({line: 1, column: sourceCode.indexOf('code')}),
       );
       done();
@@ -273,3 +275,15 @@ function createTestData() {
     transformedCode: generate(fileAst).code,
   };
 }
+
+function findColumnAndLine(text, string) {
+  const lines = text.split('\n');
+  for (let i = 0; i < lines.length; i++) {
+    const column = lines[i].indexOf(string);
+    if (column !== -1) {
+      const line = i + 1;
+      return {line, column};
+    }
+  }
+  return null;
+}
diff --git a/packages/metro-bundler/src/ModuleGraph/worker/generate.js b/packages/metro-bundler/src/ModuleGraph/worker/generate.js
index a0f2d755..321ad2b4 100644
--- a/packages/metro-bundler/src/ModuleGraph/worker/generate.js
+++ b/packages/metro-bundler/src/ModuleGraph/worker/generate.js
@@ -12,10 +12,10 @@
 
 const babelGenerate = require('babel-generator').default;
 
-function generate(ast: Object, filename: string, sourceCode: string) {
+function generate(ast: Object, filename: string, sourceCode: string, compact: boolean) {
   return babelGenerate(ast, {
     comments: false,
-    compact: true,
+    compact,
     filename,
     sourceFileName: filename,
     sourceMaps: true,
diff --git a/packages/metro-bundler/src/ModuleGraph/worker/optimize-module.js b/packages/metro-bundler/src/ModuleGraph/worker/optimize-module.js
index 7c31b3aa..ca4f7214 100644
--- a/packages/metro-bundler/src/ModuleGraph/worker/optimize-module.js
+++ b/packages/metro-bundler/src/ModuleGraph/worker/optimize-module.js
@@ -73,7 +73,7 @@ function optimize(transformed, file, originalCode, options) {
   }
 
   const inputMap = transformed.map;
-  const gen = generate(optimized.ast, file, originalCode);
+  const gen = generate(optimized.ast, file, originalCode, true);
 
   const min = minify.withSourceMap(
     gen.code,
diff --git a/packages/metro-bundler/src/ModuleGraph/worker/transform-module.js b/packages/metro-bundler/src/ModuleGraph/worker/transform-module.js
index c0ff1ae8..0719f7e9 100644
--- a/packages/metro-bundler/src/ModuleGraph/worker/transform-module.js
+++ b/packages/metro-bundler/src/ModuleGraph/worker/transform-module.js
@@ -178,7 +178,7 @@ function makeResult(ast, filename, sourceCode, isPolyfill = false) {
     file = JsFileWrapping.wrapModule(ast, dependencyMapName);
   }
 
-  const gen = generate(file, filename, sourceCode);
+  const gen = generate(file, filename, sourceCode, false);
   return {code: gen.code, map: gen.map, dependencies, dependencyMapName};
 }