diff --git a/packages/config/src/Config.ts b/packages/config/src/Config.ts
index 4df05c5c84..6e41538c57 100644
--- a/packages/config/src/Config.ts
+++ b/packages/config/src/Config.ts
@@ -7,6 +7,22 @@ import { AppJSONConfig, ExpRc, ExpoConfig, PackageJSONConfig, ProjectConfig } fr
 import { ConfigError } from './Errors';
 import { getExpoSDKVersion } from './Project';
 
+let blacklistedEnvironmentVariables = new Set([
+  'EXPO_APPLE_PASSWORD',
+  'EXPO_ANDROID_KEY_PASSWORD',
+  'EXPO_ANDROID_KEYSTORE_PASSWORD',
+  'EXPO_IOS_DIST_P12_PASSWORD',
+  'EXPO_IOS_PUSH_P12_PASSWORD',
+  'EXPO_CLI_PASSWORD',
+]);
+
+function shouldExposeEnvironmentVariableInManifest(key) {
+  if (blacklistedEnvironmentVariables.has(key.toUpperCase())) {
+    return false;
+  }
+  return key.startsWith('REACT_NATIVE_') || key.startsWith('EXPO_');
+}
+
 export function readConfigJson(
   projectRoot: string,
   skipValidation: boolean = false,
@@ -161,6 +177,13 @@ function ensureConfigHasDefaultValues(
     exp.platforms = ['android', 'ios'];
   }
 
+  exp.env = {};
+  for (let key of Object.keys(process.env)) {
+    if (shouldExposeEnvironmentVariableInManifest(key)) {
+      exp.env[key] = process.env[key];
+    }
+  }
+
   return { exp, pkg };
 }
 
diff --git a/packages/xdl/src/Project.ts b/packages/xdl/src/Project.ts
index 34a8e6ae6d..bcf8248e2a 100644
--- a/packages/xdl/src/Project.ts
+++ b/packages/xdl/src/Project.ts
@@ -1943,22 +1943,6 @@ export async function stopReactNativeServerAsync(projectRoot: string): Promise<v
   });
 }
 
-let blacklistedEnvironmentVariables = new Set([
-  'EXPO_APPLE_PASSWORD',
-  'EXPO_ANDROID_KEY_PASSWORD',
-  'EXPO_ANDROID_KEYSTORE_PASSWORD',
-  'EXPO_IOS_DIST_P12_PASSWORD',
-  'EXPO_IOS_PUSH_P12_PASSWORD',
-  'EXPO_CLI_PASSWORD',
-]);
-
-function shouldExposeEnvironmentVariableInManifest(key: string) {
-  if (blacklistedEnvironmentVariables.has(key.toUpperCase())) {
-    return false;
-  }
-  return key.startsWith('REACT_NATIVE_') || key.startsWith('EXPO_');
-}
-
 export async function startExpoServerAsync(projectRoot: string): Promise<void> {
   _assertValidProjectRoot(projectRoot);
   await stopExpoServerAsync(projectRoot);
@@ -2002,14 +1986,9 @@ export async function startExpoServerAsync(projectRoot: string): Promise<void> {
         projectRoot,
       };
       manifest.packagerOpts = packagerOpts;
-      manifest.env = {};
-      for (let key of Object.keys(process.env)) {
-        if (shouldExposeEnvironmentVariableInManifest(key)) {
-          manifest.env[key] = process.env[key];
-        }
-      }
-      let platform = (req.headers['exponent-platform'] || 'ios').toString();
-      let entryPoint = Exp.determineEntryPoint(projectRoot, platform);
+      let entryPoint = await Exp.determineEntryPointAsync(projectRoot);
+      let platform = req.headers['exponent-platform'] || 'ios';
+      entryPoint = UrlUtils.getPlatformSpecificBundleUrl(entryPoint, platform);
       let mainModuleName = UrlUtils.guessMainModulePath(entryPoint);
       let queryParams = await UrlUtils.constructBundleQueryParamsAsync(projectRoot, packagerOpts);
       let path = `/${encodeURI(mainModuleName)}.bundle?platform=${encodeURIComponent(