diff --git a/build-system/tasks/dist.js b/build-system/tasks/dist.js
index d5c453689609..744ec238d8ad 100644
--- a/build-system/tasks/dist.js
+++ b/build-system/tasks/dist.js
@@ -426,7 +426,8 @@ module.exports = {
 
 /* eslint "google-camelcase/google-camelcase": 0 */
 
-dist.description = 'Build production binaries';
+dist.description =
+  'Compiles AMP production binaries and applies AMP_CONFIG to runtime files';
 dist.flags = {
   pseudo_names:
     '  Compiles with readable names. ' +
@@ -435,6 +436,7 @@ dist.flags = {
     '  Outputs compiled code with whitespace. ' +
     'Great for debugging production code.',
   fortesting: '  Compiles production binaries for local testing',
+  noconfig: '  Compiles production binaries without applying AMP_CONFIG',
   config: '  Sets the runtime\'s AMP_CONFIG to one of "prod" or "canary"',
   single_pass: "Compile AMP's primary JS bundles in a single invocation",
   extensions: '  Builds only the listed extensions.',
diff --git a/build-system/tasks/firebase.js b/build-system/tasks/firebase.js
index b17a4c97b047..82db707e2329 100644
--- a/build-system/tasks/firebase.js
+++ b/build-system/tasks/firebase.js
@@ -18,10 +18,10 @@ const colors = require('ansi-colors');
 const fs = require('fs-extra');
 const log = require('fancy-log');
 const path = require('path');
+const {applyAmpConfig} = require('./helpers');
 const {build} = require('./build');
 const {clean} = require('./clean');
 const {dist} = require('./dist');
-const {enableLocalTesting} = require('./helpers');
 
 async function walk(dest) {
   const filelist = [];
@@ -80,8 +80,11 @@ async function firebase() {
 
   if (argv.fortesting) {
     await Promise.all([
-      enableLocalTesting('firebase/dist.3p/current/integration.js'),
-      enableLocalTesting('firebase/dist/amp.js'),
+      applyAmpConfig(
+        'firebase/dist.3p/current/integration.js',
+        /* localDev */ true
+      ),
+      applyAmpConfig('firebase/dist/amp.js', /* localDev */ true),
     ]);
   }
 
diff --git a/build-system/tasks/helpers.js b/build-system/tasks/helpers.js
index df3cea12e09c..c35877cecb5c 100644
--- a/build-system/tasks/helpers.js
+++ b/build-system/tasks/helpers.js
@@ -295,16 +295,21 @@ function compileMinifiedJs(srcDir, srcFilename, destDir, options) {
       endBuildStep('Minified', name, timeInfo.startTime);
     })
     .then(() => {
-      if (argv.fortesting && MINIFIED_TARGETS.includes(minifiedName)) {
-        return enableLocalTesting(`${destDir}/${minifiedName}`);
+      if (!argv.noconfig && MINIFIED_TARGETS.includes(minifiedName)) {
+        return applyAmpConfig(
+          `${destDir}/${minifiedName}`,
+          /* localDev */ !!argv.fortesting
+        );
       }
     })
     .then(() => {
-      if (!argv.fortesting || !options.singlePassCompilation) {
+      if (argv.noconfig || !options.singlePassCompilation) {
         return;
       }
       return Promise.all(
-        altMainBundles.map(({name}) => enableLocalTesting(`dist/${name}.js`))
+        altMainBundles.map(({name}) =>
+          applyAmpConfig(`dist/${name}.js`, /* localDev */ !!argv.fortesting)
+        )
       );
     });
 }
@@ -443,7 +448,10 @@ function compileUnminifiedJs(srcDir, srcFilename, destDir, options) {
       })
       .then(() => {
         if (UNMINIFIED_TARGETS.includes(destFilename)) {
-          return enableLocalTesting(`${destDir}/${destFilename}`);
+          return applyAmpConfig(
+            `${destDir}/${destFilename}`,
+            /* localDev */ true
+          );
         }
       });
   }
@@ -555,12 +563,14 @@ function printNobuildHelp() {
 }
 
 /**
- * Enables runtime to be used for local testing by writing AMP_CONFIG to file.
- * Called at the end of "gulp build" and "gulp dist --fortesting".
+ * Writes AMP_CONFIG to a runtime file. Optionally enables localDev mode and
+ * fortesting mode. Called by "gulp build" and "gulp dist" while building
+ * various runtime files.
  * @param {string} targetFile File to which the config is to be written.
+ * @param {boolean} localDev Whether or not to enable local development.
  * @return {!Promise}
  */
-async function enableLocalTesting(targetFile) {
+async function applyAmpConfig(targetFile, localDev) {
   const config = argv.config === 'canary' ? 'canary' : 'prod';
   const baseConfigFile =
     'build-system/global-configs/' + config + '-config.json';
@@ -570,7 +580,7 @@ async function enableLocalTesting(targetFile) {
       config,
       targetFile,
       baseConfigFile,
-      /* opt_localDev */ true,
+      /* opt_localDev */ localDev,
       /* opt_localBranch */ true,
       /* opt_branch */ false,
       /* opt_fortesting */ !!argv.fortesting
@@ -696,6 +706,7 @@ function transferSrcsToTempDir(options = {}) {
 }
 
 module.exports = {
+  applyAmpConfig,
   BABELIFY_GLOBAL_TRANSFORM,
   BABELIFY_PLUGINS,
   bootstrapThirdPartyFrames,
@@ -706,7 +717,6 @@ module.exports = {
   compileTs,
   devDependencies,
   doBuildJs,
-  enableLocalTesting,
   endBuildStep,
   hostname,
   mkdirSync,
diff --git a/contributing/TESTING.md b/contributing/TESTING.md
index cc64d1046f82..fb34b5334d63 100644
--- a/contributing/TESTING.md
+++ b/contributing/TESTING.md
@@ -48,7 +48,8 @@ Before running these commands, make sure you have Node.js, yarn, and Gulp instal
 | `gulp --extensions=minimal_set`                           | Runs "watch" and "serve", after building the extensions needed to load `article.amp.html`.                                                                                                                                                    |
 | `gulp --extensions_from=examples/foo.amp.html`            | Runs "watch" and "serve", after building only extensions from the listed examples.                                                                                                                                                            |
 | `gulp --noextensions`                                     | Runs "watch" and "serve" without building any extensions.                                                                                                                                                                                     |
-| `gulp dist`                                               | Builds production binaries.                                                                                                                                                                                                                   |
+| `gulp dist`                                               | Builds production binaries and applies AMP_CONFIG to runtime files.                                                                                                                                                                           |
+| `gulp dist --noconfig`                                    | Builds production binaries without applying AMP_CONFIG to runtime files.                                                                                                                                                                      |
 | `gulp dist --extensions=amp-foo,amp-bar`                  | Builds production binaries, with only the listed extensions.                                                                                                                                                                                  |
 | `gulp dist --extensions=minimal_set`                      | Builds production binaries, with only the extensions needed to load `article.amp.html`.                                                                                                                                                       |
 | `gulp dist --extensions_from=examples/foo.amp.html`       | Builds production binaries, with only extensions from the listed examples.                                                                                                                                                                    |