diff --git a/python/mozbuild/mozbuild/action/test_archive.py b/python/mozbuild/mozbuild/action/test_archive.py
index bb6c073591a1..308369cb6e05 100644
--- a/python/mozbuild/mozbuild/action/test_archive.py
+++ b/python/mozbuild/mozbuild/action/test_archive.py
@@ -478,6 +478,16 @@ ARCHIVE_FILES = {
     ],
 }
 
+if buildconfig.substs.get('MOZ_CODE_COVERAGE'):
+    ARCHIVE_FILES['common'].append({
+        'source': buildconfig.topsrcdir,
+        'base': 'python/mozbuild/',
+        'patterns': [
+            'mozpack/**',
+            'mozbuild/codecoverage/**',
+        ],
+    })
+
 
 if buildconfig.substs.get('MOZ_ASAN') and buildconfig.substs.get('CLANG_CL'):
     asan_dll = {
diff --git a/testing/mozharness/configs/unittests/linux_unittest.py b/testing/mozharness/configs/unittests/linux_unittest.py
index 0be74d31e313..98b1413a0b8e 100644
--- a/testing/mozharness/configs/unittests/linux_unittest.py
+++ b/testing/mozharness/configs/unittests/linux_unittest.py
@@ -67,6 +67,8 @@ config = {
         "modules/*",
         "mozbase/*",
         "tools/*",
+        "mozpack/*",
+        "mozbuild/*",
     ],
     "specific_tests_zip_dirs": {
         "mochitest": ["mochitest/*"],
diff --git a/testing/mozharness/configs/unittests/win_taskcluster_unittest.py b/testing/mozharness/configs/unittests/win_taskcluster_unittest.py
index 63fc4ab0505c..049098c915f4 100644
--- a/testing/mozharness/configs/unittests/win_taskcluster_unittest.py
+++ b/testing/mozharness/configs/unittests/win_taskcluster_unittest.py
@@ -61,6 +61,8 @@ config = {
         "modules/*",
         "mozbase/*",
         "tools/*",
+        "mozpack/*",
+        "mozbuild/*",
     ],
     "specific_tests_zip_dirs": {
         "mochitest": ["mochitest/*"],
diff --git a/testing/mozharness/configs/unittests/win_unittest.py b/testing/mozharness/configs/unittests/win_unittest.py
index 18125a67f9f1..34911d743e5a 100644
--- a/testing/mozharness/configs/unittests/win_unittest.py
+++ b/testing/mozharness/configs/unittests/win_unittest.py
@@ -52,6 +52,8 @@ config = {
         "modules/*",
         "mozbase/*",
         "tools/*",
+        "mozpack/*",
+        "mozbuild/*",
     ],
     "specific_tests_zip_dirs": {
         "mochitest": ["mochitest/*"],
diff --git a/testing/mozharness/mozharness/mozilla/testing/firefox_ui_tests.py b/testing/mozharness/mozharness/mozilla/testing/firefox_ui_tests.py
index 5105b3d6633d..45d3dcdc9a6c 100644
--- a/testing/mozharness/mozharness/mozilla/testing/firefox_ui_tests.py
+++ b/testing/mozharness/mozharness/mozilla/testing/firefox_ui_tests.py
@@ -152,6 +152,8 @@ class FirefoxUITests(TestingMixin, VCSToolsScript, CodeCoverageMixin):
                         'mozbase/*',
                         'tools/mozterm/*',
                         'tools/wptserve/*',
+                        'mozpack/*',
+                        'mozbuild/*',
                         ]
         super(FirefoxUITests, self).download_and_extract(extract_dirs=extract_dirs)
 
diff --git a/testing/mozharness/scripts/web_platform_tests.py b/testing/mozharness/scripts/web_platform_tests.py
index 98b92e4ce84b..8390d8f1f133 100755
--- a/testing/mozharness/scripts/web_platform_tests.py
+++ b/testing/mozharness/scripts/web_platform_tests.py
@@ -277,7 +277,9 @@ class WebPlatformTest(TestingMixin, MercurialScript, BlobUploadMixin, CodeCovera
                           "mozbase/*",
                           "marionette/*",
                           "tools/*",
-                          "web-platform/*"],
+                          "web-platform/*",
+                          "mozpack/*",
+                          "mozbuild/*"],
             suite_categories=["web-platform"])
 
     def _install_fonts(self):