diff --git a/google/cloud/secretmanager/v1/BUILD.bazel b/google/cloud/secretmanager/v1/BUILD.bazel
index fb91c8d2f..3b6b97b0f 100644
--- a/google/cloud/secretmanager/v1/BUILD.bazel
+++ b/google/cloud/secretmanager/v1/BUILD.bazel
@@ -238,6 +238,7 @@ php_gapic_library(
     rest_numeric_enums = True,
     service_yaml = "secretmanager_v1.yaml",
     transport = "grpc+rest",
+    migration_mode = "MIGRATING",
     deps = [
         ":secretmanager_php_grpc",
         ":secretmanager_php_proto",