diff --git a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_applications.py b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_applications.py
index 205bbeb38a4c..dcd6dfbbdbad 100644
--- a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_applications.py
+++ b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_applications.py
@@ -14,7 +14,13 @@
 # limitations under the License.
 #
 import os
-import mock
+
+# try/except added for compatibility with python < 3.8
+try:
+    from unittest import mock
+    from unittest.mock import AsyncMock
+except ImportError:
+    import mock
 
 import grpc
 from grpc.experimental import aio
diff --git a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_authorized_certificates.py b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_authorized_certificates.py
index 9e95c2e5dd78..b19deae8db4f 100644
--- a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_authorized_certificates.py
+++ b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_authorized_certificates.py
@@ -14,7 +14,13 @@
 # limitations under the License.
 #
 import os
-import mock
+
+# try/except added for compatibility with python < 3.8
+try:
+    from unittest import mock
+    from unittest.mock import AsyncMock
+except ImportError:
+    import mock
 
 import grpc
 from grpc.experimental import aio
diff --git a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_authorized_domains.py b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_authorized_domains.py
index 19b8ae1d826a..6a618f616c8a 100644
--- a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_authorized_domains.py
+++ b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_authorized_domains.py
@@ -14,7 +14,13 @@
 # limitations under the License.
 #
 import os
-import mock
+
+# try/except added for compatibility with python < 3.8
+try:
+    from unittest import mock
+    from unittest.mock import AsyncMock
+except ImportError:
+    import mock
 
 import grpc
 from grpc.experimental import aio
diff --git a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_domain_mappings.py b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_domain_mappings.py
index 4ddf609f2d32..76999df7d08a 100644
--- a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_domain_mappings.py
+++ b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_domain_mappings.py
@@ -14,7 +14,13 @@
 # limitations under the License.
 #
 import os
-import mock
+
+# try/except added for compatibility with python < 3.8
+try:
+    from unittest import mock
+    from unittest.mock import AsyncMock
+except ImportError:
+    import mock
 
 import grpc
 from grpc.experimental import aio
diff --git a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_firewall.py b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_firewall.py
index 929120543795..dea4bbd4953b 100644
--- a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_firewall.py
+++ b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_firewall.py
@@ -14,7 +14,13 @@
 # limitations under the License.
 #
 import os
-import mock
+
+# try/except added for compatibility with python < 3.8
+try:
+    from unittest import mock
+    from unittest.mock import AsyncMock
+except ImportError:
+    import mock
 
 import grpc
 from grpc.experimental import aio
diff --git a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_instances.py b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_instances.py
index 14a3adef34bf..22591dd1967d 100644
--- a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_instances.py
+++ b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_instances.py
@@ -14,7 +14,13 @@
 # limitations under the License.
 #
 import os
-import mock
+
+# try/except added for compatibility with python < 3.8
+try:
+    from unittest import mock
+    from unittest.mock import AsyncMock
+except ImportError:
+    import mock
 
 import grpc
 from grpc.experimental import aio
diff --git a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_services.py b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_services.py
index 9b60574980eb..c2a22ff14719 100644
--- a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_services.py
+++ b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_services.py
@@ -14,7 +14,13 @@
 # limitations under the License.
 #
 import os
-import mock
+
+# try/except added for compatibility with python < 3.8
+try:
+    from unittest import mock
+    from unittest.mock import AsyncMock
+except ImportError:
+    import mock
 
 import grpc
 from grpc.experimental import aio
diff --git a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_versions.py b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_versions.py
index 9bf3cd12cb22..d66081a2bb5b 100644
--- a/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_versions.py
+++ b/packages/google-cloud-appengine-admin/tests/unit/gapic/appengine_admin_v1/test_versions.py
@@ -14,7 +14,13 @@
 # limitations under the License.
 #
 import os
-import mock
+
+# try/except added for compatibility with python < 3.8
+try:
+    from unittest import mock
+    from unittest.mock import AsyncMock
+except ImportError:
+    import mock
 
 import grpc
 from grpc.experimental import aio