diff --git a/Libraries/WebSocket/RCTWebSocket.xcodeproj/project.pbxproj b/Libraries/WebSocket/RCTWebSocket.xcodeproj/project.pbxproj
index 742b905842a01f..8121ed0c108179 100644
--- a/Libraries/WebSocket/RCTWebSocket.xcodeproj/project.pbxproj
+++ b/Libraries/WebSocket/RCTWebSocket.xcodeproj/project.pbxproj
@@ -436,7 +436,7 @@
 				GCC_PREPROCESSOR_DEFINITIONS = (
 					"DEBUG=1",
 					"$(inherited)",
-					"RCT_PACKAGER_PORT=${RCT_PACKAGER_PORT}",
+					"RCT_METRO_PORT=${RCT_METRO_PORT}",
 				);
 				GCC_TREAT_WARNINGS_AS_ERRORS = NO;
 				OTHER_LDFLAGS = "-ObjC";
@@ -448,7 +448,7 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				EXECUTABLE_PREFIX = lib;
-				GCC_PREPROCESSOR_DEFINITIONS = "RCT_PACKAGER_PORT=${RCT_PACKAGER_PORT}";
+				GCC_PREPROCESSOR_DEFINITIONS = "RCT_METRO_PORT=${RCT_METRO_PORT}";
 				GCC_TREAT_WARNINGS_AS_ERRORS = NO;
 				OTHER_LDFLAGS = "-ObjC";
 				PRODUCT_NAME = "$(TARGET_NAME)";
diff --git a/Libraries/WebSocket/RCTWebSocketExecutor.h b/Libraries/WebSocket/RCTWebSocketExecutor.h
index 733da2adb7cc40..8e5664538bcbbb 100644
--- a/Libraries/WebSocket/RCTWebSocketExecutor.h
+++ b/Libraries/WebSocket/RCTWebSocketExecutor.h
@@ -12,6 +12,10 @@
 
 #if RCT_DEV // Debug executors are only supported in dev mode
 
+#ifndef RCT_METRO_PORT
+#define RCT_METRO_PORT 8081
+#endif
+
 @interface RCTWebSocketExecutor : NSObject <RCTJavaScriptExecutor>
 
 - (instancetype)initWithURL:(NSURL *)URL;
diff --git a/Libraries/WebSocket/RCTWebSocketExecutor.m b/Libraries/WebSocket/RCTWebSocketExecutor.m
index 1f7dc1d9ef3a6d..b292c4f9b8ca15 100644
--- a/Libraries/WebSocket/RCTWebSocketExecutor.m
+++ b/Libraries/WebSocket/RCTWebSocketExecutor.m
@@ -54,7 +54,7 @@ - (instancetype)initWithURL:(NSURL *)URL
 - (void)setUp
 {
   if (!_url) {
-    NSInteger port = [[[_bridge bundleURL] port] integerValue] ?: RCT_PACKAGER_PORT;
+    NSInteger port = [[[_bridge bundleURL] port] integerValue] ?: RCT_METRO_PORT;
     NSString *host = [[_bridge bundleURL] host] ?: @"localhost";
     NSString *URLString = [NSString stringWithFormat:@"http://%@:%lld/debugger-proxy?role=client", host, (long long)port];
     _url = [RCTConvert NSURL:URLString];
diff --git a/React/Base/RCTBundleURLProvider.h b/React/Base/RCTBundleURLProvider.h
index efc9be73bac36f..e6ade241eeb926 100644
--- a/React/Base/RCTBundleURLProvider.h
+++ b/React/Base/RCTBundleURLProvider.h
@@ -9,6 +9,10 @@
 
 #import <Foundation/Foundation.h>
 
+#ifndef RCT_METRO_PORT
+#define RCT_METRO_PORT 8081
+#endif
+
 extern NSString *const RCTBundleURLProviderUpdatedNotification;
 
 extern const NSUInteger kRCTBundleURLProviderDefaultPort;
diff --git a/React/Base/RCTBundleURLProvider.m b/React/Base/RCTBundleURLProvider.m
index 29407508516d62..61c286ec4518d6 100644
--- a/React/Base/RCTBundleURLProvider.m
+++ b/React/Base/RCTBundleURLProvider.m
@@ -14,7 +14,7 @@
 
 NSString *const RCTBundleURLProviderUpdatedNotification = @"RCTBundleURLProviderUpdatedNotification";
 
-const NSUInteger kRCTBundleURLProviderDefaultPort = RCT_PACKAGER_PORT;
+const NSUInteger kRCTBundleURLProviderDefaultPort = RCT_METRO_PORT;
 
 static NSString *const kRCTJsLocationKey = @"RCT_jsLocation";
 static NSString *const kRCTEnableLiveReloadKey = @"RCT_enableLiveReload";
diff --git a/React/React.xcodeproj/project.pbxproj b/React/React.xcodeproj/project.pbxproj
index 77343823442b15..a4a87f509da74b 100644
--- a/React/React.xcodeproj/project.pbxproj
+++ b/React/React.xcodeproj/project.pbxproj
@@ -3724,7 +3724,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
-			shellScript = "export RCT_PACKAGER_PORT=\"${RCT_PACKAGER_PORT:-8081}\"\necho \"export RCT_PACKAGER_PORT=${RCT_PACKAGER_PORT}\" > \"${SRCROOT}/../scripts/.packager.env\"\nif [ -z \"${RCT_NO_LAUNCH_PACKAGER+xxx}\" ] ; then\n  if nc -w 5 -z localhost ${RCT_PACKAGER_PORT} ; then\n    if ! curl -s \"http://localhost:${RCT_PACKAGER_PORT}/status\" | grep -q \"packager-status:running\" ; then\n      echo \"Port ${RCT_PACKAGER_PORT} already in use, packager is either not running or not running correctly\"\n      exit 2\n    fi\n  else\n    open \"$SRCROOT/../scripts/launchPackager.command\" || echo \"Can't start packager automatically\"\n  fi\nfi";
+			shellScript = "export RCT_METRO_PORT=\"${RCT_METRO_PORT:-8081}\"\necho \"export RCT_METRO_PORT=${RCT_METRO_PORT}\" > \"${SRCROOT}/../scripts/.packager.env\"\nif [ -z \"${RCT_NO_LAUNCH_PACKAGER+xxx}\" ] ; then\n  if nc -w 5 -z localhost ${RCT_METRO_PORT} ; then\n    if ! curl -s \"http://localhost:${RCT_METRO_PORT}/status\" | grep -q \"packager-status:running\" ; then\n      echo \"Port ${RCT_METRO_PORT} already in use, packager is either not running or not running correctly\"\n      exit 2\n    fi\n  else\n    open \"$SRCROOT/../scripts/launchPackager.command\" || echo \"Can't start packager automatically\"\n  fi\nfi";
 			showEnvVarsInLog = 0;
 		};
 		142C4F7F1B582EA6001F0B58 /* Include RCTJSCProfiler */ = {
@@ -4831,7 +4831,7 @@
 					"RCT_DEBUG=1",
 					"RCT_DEV=1",
 					"RCT_NSASSERT=1",
-					"RCT_PACKAGER_PORT=${RCT_PACKAGER_PORT}",
+					"RCT_METRO_PORT=${RCT_METRO_PORT}",
 				);
 				GCC_WARN_ABOUT_MISSING_NEWLINE = YES;
 				OTHER_LDFLAGS = "-ObjC";
@@ -4849,7 +4849,7 @@
 				CLANG_STATIC_ANALYZER_MODE = deep;
 				GCC_PREPROCESSOR_DEFINITIONS = (
 					"$(inherited)",
-					"RCT_PACKAGER_PORT=${RCT_PACKAGER_PORT}",
+					"RCT_METRO_PORT=${RCT_METRO_PORT}",
 				);
 				GCC_WARN_ABOUT_MISSING_NEWLINE = YES;
 				OTHER_LDFLAGS = "-ObjC";
diff --git a/local-cli/runAndroid/runAndroid.js b/local-cli/runAndroid/runAndroid.js
index a1ae11d57afead..47070821371934 100644
--- a/local-cli/runAndroid/runAndroid.js
+++ b/local-cli/runAndroid/runAndroid.js
@@ -273,7 +273,7 @@ function startServerInNewWindow(port) {
 
   // setup the .packager.env file to ensure the packager starts on the right port
   const packagerEnvFile = path.join(__dirname, '..', '..', 'scripts', '.packager.env');
-  const content = `export RCT_PACKAGER_PORT=${port}`;
+  const content = `export RCT_METRO_PORT=${port}`;
   fs.writeFileSync(packagerEnvFile,content,{encoding: 'utf8', flag:'w'}); // passing the 'w' flag will overwrite the file
 
   if (process.platform === 'darwin') {
@@ -338,7 +338,7 @@ module.exports = {
     description: 'Do not launch packager while building',
   }, {
     command: '--port [number]',
-    default: process.env.RCT_PACKAGER_PORT || 8081,
+    default: process.env.RCT_METRO_PORT || 8081,
     parse: (val: string) => Number(val),
   }],
 };
diff --git a/local-cli/runIOS/runIOS.js b/local-cli/runIOS/runIOS.js
index 617bc7fca21084..1dce9c2939420b 100644
--- a/local-cli/runIOS/runIOS.js
+++ b/local-cli/runIOS/runIOS.js
@@ -235,7 +235,7 @@ function printFoundDevices(devices) {
 function getProcessOptions(launchPackager, port) {
   if (launchPackager) {
     return {
-      env: { ...process.env, RCT_PACKAGER_PORT: port }
+      env: { ...process.env, RCT_METRO_PORT: port }
     };
   }
 
@@ -291,7 +291,7 @@ module.exports = {
     description: 'Do not use xcpretty even if installed',
   },{
     command: '--port [number]',
-    default: process.env.RCT_PACKAGER_PORT || 8081,
+    default: process.env.RCT_METRO_PORT || 8081,
     parse: (val: string) => Number(val),
   }],
 };
diff --git a/local-cli/server/server.js b/local-cli/server/server.js
index 6ad03eaa9fae3b..fe151798ef24d5 100644
--- a/local-cli/server/server.js
+++ b/local-cli/server/server.js
@@ -60,7 +60,7 @@ module.exports = {
   description: 'starts the webserver',
   options: [{
     command: '--port [number]',
-    default: process.env.RCT_PACKAGER_PORT || 8081,
+    default: process.env.RCT_METRO_PORT || 8081,
     parse: (val: string) => Number(val),
   }, {
     command: '--host [string]',
diff --git a/local-cli/util/isPackagerRunning.js b/local-cli/util/isPackagerRunning.js
index be0090b089e429..fbdebd08d255f9 100644
--- a/local-cli/util/isPackagerRunning.js
+++ b/local-cli/util/isPackagerRunning.js
@@ -19,7 +19,7 @@ const fetch = require('node-fetch');
  *   - `unrecognized`: one other process is running on the port we expect the
  *                     packager to be running.
  */
-function isPackagerRunning(packagerPort = (process.env.RCT_PACKAGER_PORT || 8081)) {
+function isPackagerRunning(packagerPort = (process.env.RCT_METRO_PORT || 8081)) {
   return fetch(`http://localhost:${packagerPort}/status`).then(
     res => res.text().then(body =>
       body === 'packager-status:running' ? 'running' : 'unrecognized'