diff --git a/packages/google-api-core/google/api_core/gapic_v1/__init__.py b/packages/google-api-core/google/api_core/gapic_v1/__init__.py
index e5b7ad352ee6..547a7aad085d 100644
--- a/packages/google-api-core/google/api_core/gapic_v1/__init__.py
+++ b/packages/google-api-core/google/api_core/gapic_v1/__init__.py
@@ -12,6 +12,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from typing import Set
+
+__lazy_modules__: Set[str] = {
+    "google.api_core.gapic_v1.client_info",
+    "google.api_core.gapic_v1.config",
+    "google.api_core.gapic_v1.config_async",
+    "google.api_core.gapic_v1.method",
+    "google.api_core.gapic_v1.method_async",
+    "google.api_core.gapic_v1.routing_header",
+}
+
 from google.api_core.gapic_v1 import client_info
 from google.api_core.gapic_v1 import config
 from google.api_core.gapic_v1 import config_async