diff --git a/gulpfile.js b/gulpfile.js
index 4af66b12a9..462c52f36d 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -416,9 +416,27 @@ gulp.task('docs/angular.io', ['build/clean.docs_angular_io'], function() {
 // CI tests suites
 
 function runKarma(configFile, done) {
+  var fs = require('fs');
+  var path = require('path');
   var cmd = process.platform === 'win32' ? 'node_modules\\.bin\\karma run ' :
                                            'node node_modules/.bin/karma run ';
   cmd += configFile;
+
+  // this file is written into the tmp folder by DestCopy broccoli plugin after each build
+  var karmaArgsPath = path.join('tmp', 'build-log-karma-args.txt');
+
+  if (fs.existsSync(karmaArgsPath)) {
+    var changedFilesArgs = fs.readFileSync(karmaArgsPath, {encoding: 'utf-8'});
+
+    // windows has a limit for the length of the command it can execute, so on win we check the
+    // length of args provide them only if the length is not over the limit.
+    // additionally, the arguments don't help the speedup the initial run, so we can safely ignore
+    // the args when there is lots of them on all platforms
+    if (changedFilesArgs.length > 10 && changedFilesArgs.length + cmd.length < 0x2000) {
+      cmd += changedFilesArgs;
+    }
+  }
+
   exec(cmd, function(e, stdout) {
     // ignore errors, we don't want to fail the build in the interactive (non-ci) mode
     // karma server will print all test failures
diff --git a/tools/broccoli/broccoli-dest-copy.ts b/tools/broccoli/broccoli-dest-copy.ts
index ecfd90a482..87152ea7a7 100644
--- a/tools/broccoli/broccoli-dest-copy.ts
+++ b/tools/broccoli/broccoli-dest-copy.ts
@@ -30,6 +30,20 @@ class DestCopy implements DiffingBroccoliPlugin {
       // TODO: what about obsolete directories? we are not cleaning those up yet
       fs.unlinkSync(destFilePath);
     });
+
+
+    // Write log of added/changed/removed files to be used when we call `karma run` from gulp.
+    var karmaArgs = '';
+    if (treeDiff.addedPaths.length) {
+      karmaArgs +=  ' --addedFiles ' + treeDiff.addedPaths.join(',');
+    }
+    if (treeDiff.changedPaths.length) {
+      karmaArgs +=  ' --changedFiles ' + treeDiff.changedPaths.join(',');
+    }
+    if (treeDiff.removedPaths.length) {
+      karmaArgs +=  ' --removedFiles ' + treeDiff.removedPaths.join(',')
+    }
+    fs.writeFileSync(path.join('tmp', 'build-log-karma-args.txt'), karmaArgs, {encoding: 'utf-8'});
   }
 }