diff --git a/packages/metro/src/ModuleGraph/ModuleGraph.js b/packages/metro/src/ModuleGraph/ModuleGraph.js
index e6491049..d0d49af2 100644
--- a/packages/metro/src/ModuleGraph/ModuleGraph.js
+++ b/packages/metro/src/ModuleGraph/ModuleGraph.js
@@ -66,6 +66,7 @@ exports.createBuildSetup = (
 function prelude(optimize) {
   return virtualModule(
     `var __DEV__=${String(!optimize)},` +
-      '__BUNDLE_START_TIME__=this.nativePerformanceNow?nativePerformanceNow():Date.now();',
+      '__BUNDLE_START_TIME__=this.nativePerformanceNow?nativePerformanceNow():Date.now(),' +
+      `process={env:{NODE_ENV:'${optimize ? 'production' : 'development'}'}};`,
   );
 }
diff --git a/packages/metro/src/ModuleGraph/__tests__/ModuleGraph-test.js b/packages/metro/src/ModuleGraph/__tests__/ModuleGraph-test.js
index b955064b..06621fb5 100644
--- a/packages/metro/src/ModuleGraph/__tests__/ModuleGraph-test.js
+++ b/packages/metro/src/ModuleGraph/__tests__/ModuleGraph-test.js
@@ -35,7 +35,8 @@ describe('build setup', () => {
       file: {
         code:
           'var __DEV__=true,__BUNDLE_START_TIME__=' +
-          'this.nativePerformanceNow?nativePerformanceNow():Date.now();',
+          'this.nativePerformanceNow?nativePerformanceNow():Date.now(),' +
+          "process={env:{NODE_ENV:'development'}};",
         map: null,
         path: '',
         type: 'script',
@@ -48,7 +49,8 @@ describe('build setup', () => {
     const [prelude] = result.modules;
     expect(prelude.file.code).toEqual(
       'var __DEV__=false,__BUNDLE_START_TIME__=' +
-        'this.nativePerformanceNow?nativePerformanceNow():Date.now();',
+        'this.nativePerformanceNow?nativePerformanceNow():Date.now(),' +
+        "process={env:{NODE_ENV:'production'}};",
     );
   });
 
diff --git a/packages/metro/src/Resolver/polyfills/prelude.js b/packages/metro/src/Resolver/polyfills/prelude.js
index c4afe04a..62493f86 100644
--- a/packages/metro/src/Resolver/polyfills/prelude.js
+++ b/packages/metro/src/Resolver/polyfills/prelude.js
@@ -15,3 +15,5 @@ global.__DEV__ = false;
 global.__BUNDLE_START_TIME__ = global.nativePerformanceNow
   ? global.nativePerformanceNow()
   : Date.now();
+
+global.process = {env: {NODE_ENV: 'production'}};
diff --git a/packages/metro/src/Resolver/polyfills/prelude_dev.js b/packages/metro/src/Resolver/polyfills/prelude_dev.js
index 068785bc..c615f723 100644
--- a/packages/metro/src/Resolver/polyfills/prelude_dev.js
+++ b/packages/metro/src/Resolver/polyfills/prelude_dev.js
@@ -15,3 +15,5 @@ global.__DEV__ = true;
 global.__BUNDLE_START_TIME__ = global.nativePerformanceNow
   ? global.nativePerformanceNow()
   : Date.now();
+
+global.process = {env: {NODE_ENV: 'development'}};
diff --git a/packages/metro/src/integration_tests/__tests__/__snapshots__/basic_bundle-test.js.snap b/packages/metro/src/integration_tests/__tests__/__snapshots__/basic_bundle-test.js.snap
index 36c76c9d..46d79572 100644
--- a/packages/metro/src/integration_tests/__tests__/__snapshots__/basic_bundle-test.js.snap
+++ b/packages/metro/src/integration_tests/__tests__/__snapshots__/basic_bundle-test.js.snap
@@ -4,6 +4,11 @@ exports[`basic_bundle bundles package with polyfills 1`] = `
 "(function (global) {
   global.__DEV__ = false;
   global.__BUNDLE_START_TIME__ = global.nativePerformanceNow ? global.nativePerformanceNow() : Date.now();
+  global.process = {
+    env: {
+      NODE_ENV: 'production'
+    }
+  };
 })(this);
 (function (global) {
   'use strict';
@@ -195,6 +200,11 @@ exports[`basic_bundle bundles package without polyfills 1`] = `
 "(function (global) {
   global.__DEV__ = false;
   global.__BUNDLE_START_TIME__ = global.nativePerformanceNow ? global.nativePerformanceNow() : Date.now();
+  global.process = {
+    env: {
+      NODE_ENV: 'production'
+    }
+  };
 })(this);
 (function (global) {
   'use strict';