diff --git a/packages/google-cloud-kms/google/cloud/kms_v1/gapic/transports/key_management_service_grpc_transport.py b/packages/google-cloud-kms/google/cloud/kms_v1/gapic/transports/key_management_service_grpc_transport.py
index 59f1576c0c0b..52dfd68581e4 100644
--- a/packages/google-cloud-kms/google/cloud/kms_v1/gapic/transports/key_management_service_grpc_transport.py
+++ b/packages/google-cloud-kms/google/cloud/kms_v1/gapic/transports/key_management_service_grpc_transport.py
@@ -18,7 +18,7 @@
 import google.api_core.grpc_helpers
 
 from google.cloud.kms_v1.proto import service_pb2_grpc
-from google.iam.v1 import iam_policy_pb2
+from google.iam.v1 import iam_policy_pb2_grpc as iam_policy_pb2
 
 
 class KeyManagementServiceGrpcTransport(object):
diff --git a/packages/google-cloud-kms/setup.py b/packages/google-cloud-kms/setup.py
index f3a1d7c71662..e53a9748b029 100644
--- a/packages/google-cloud-kms/setup.py
+++ b/packages/google-cloud-kms/setup.py
@@ -25,7 +25,7 @@
 release_status = "Development Status :: 5 - Production/Stable"
 dependencies = [
     "google-api-core[grpc] >= 1.6.0, < 2.0.0dev",
-    "grpc-google-iam-v1 >= 0.11.4, < 0.12dev",
+    "grpc-google-iam-v1 >= 0.12.3, < 0.13dev",
     'enum34; python_version < "3.4"',
 ]
 
diff --git a/packages/google-cloud-kms/synth.py b/packages/google-cloud-kms/synth.py
index c216ae7b85f1..e1570a7284e0 100644
--- a/packages/google-cloud-kms/synth.py
+++ b/packages/google-cloud-kms/synth.py
@@ -39,6 +39,13 @@
 
 s.move(library, excludes=["README.rst", "setup.py", "nox*.py", "docs/**/*"])
 
+# Temporary fixup for 'grpc-google-iam-vi 0.12.4' (before generation).
+s.replace(
+    "google/cloud/kms_v1/gapic/transports/key_management_service_grpc_transport.py",
+    "from google.iam.v1 import iam_policy_pb2",
+    "from google.iam.v1 import iam_policy_pb2_grpc as iam_policy_pb2",
+)
+
 # ----------------------------------------------------------------------------
 # Add templated files
 # ----------------------------------------------------------------------------