diff --git a/packages/angular_devkit/build_angular/src/webpack/plugins/karma/karma-context.html b/packages/angular_devkit/build_angular/src/webpack/plugins/karma/karma-context.html
index 587278156358..854f6eaed0a1 100644
--- a/packages/angular_devkit/build_angular/src/webpack/plugins/karma/karma-context.html
+++ b/packages/angular_devkit/build_angular/src/webpack/plugins/karma/karma-context.html
@@ -30,13 +30,13 @@
       // All served files with the latest timestamps
       %MAPPINGS%
     </script>
-    <script src="_karma_webpack_/runtime.js" crossorigin="anonymous"></script>
-    <script src="_karma_webpack_/polyfills.js" crossorigin="anonymous"></script>
+    <script src="_karma_webpack_/runtime.js" crossorigin="anonymous" type="module"></script>
+    <script src="_karma_webpack_/polyfills.js" crossorigin="anonymous" type="module"></script>
     <!-- Dynamically replaced with <script> tags -->
     %SCRIPTS%
-    <script src="_karma_webpack_/scripts.js" crossorigin="anonymous"></script>
-    <script src="_karma_webpack_/vendor.js" crossorigin="anonymous"></script>
-    <script src="_karma_webpack_/main.js" crossorigin="anonymous"></script>
+    <script src="_karma_webpack_/scripts.js" crossorigin="anonymous" defer></script>
+    <script src="_karma_webpack_/vendor.js" crossorigin="anonymous" type="module"></script>
+    <script src="_karma_webpack_/main.js" crossorigin="anonymous" type="module"></script>
     <script type="text/javascript">
       window.__karma__.loaded();
     </script>
diff --git a/packages/angular_devkit/build_angular/src/webpack/plugins/karma/karma-debug.html b/packages/angular_devkit/build_angular/src/webpack/plugins/karma/karma-debug.html
index fed09ab2a369..b908826c2ce4 100644
--- a/packages/angular_devkit/build_angular/src/webpack/plugins/karma/karma-debug.html
+++ b/packages/angular_devkit/build_angular/src/webpack/plugins/karma/karma-debug.html
@@ -32,13 +32,13 @@
       // All served files with the latest timestamps
       %MAPPINGS%
     </script>
-    <script src="_karma_webpack_/runtime.js" crossorigin="anonymous"></script>
-    <script src="_karma_webpack_/polyfills.js" crossorigin="anonymous"></script>
+    <script src="_karma_webpack_/runtime.js" crossorigin="anonymous" type="module"></script>
+    <script src="_karma_webpack_/polyfills.js" crossorigin="anonymous" type="module"></script>
     <!-- Dynamically replaced with <script> tags -->
     %SCRIPTS%
-    <script src="_karma_webpack_/scripts.js" crossorigin="anonymous"></script>
-    <script src="_karma_webpack_/vendor.js" crossorigin="anonymous"></script>
-    <script src="_karma_webpack_/main.js" crossorigin="anonymous"></script>
+    <script src="_karma_webpack_/scripts.js" crossorigin="anonymous" defer></script>
+    <script src="_karma_webpack_/vendor.js" crossorigin="anonymous" type="module"></script>
+    <script src="_karma_webpack_/main.js" crossorigin="anonymous" type="module"></script>
     <script type="text/javascript">
       window.__karma__.loaded();
     </script>