diff --git a/packages/google-cloud-automl/setup.py b/packages/google-cloud-automl/setup.py
index da5620c39f75..673bde914005 100644
--- a/packages/google-cloud-automl/setup.py
+++ b/packages/google-cloud-automl/setup.py
@@ -24,7 +24,7 @@
 dependencies = [
     "google-api-core[grpc] >= 1.32.0, <3.0.0dev,!=2.0.*,!=2.1.*,!=2.2.*,!=2.3.*,!=2.4.*,!=2.5.*,!=2.6.*,!=2.7.*",
     "proto-plus >= 1.22.0, <2.0.0dev",
-    "protobuf >= 3.20.2, <5.0.0dev",
+    "protobuf>=3.19.5,<5.0.0dev,!=3.20.0,!=3.20.1,!=4.21.0,!=4.21.1,!=4.21.2,!=4.21.3,!=4.21.4,!=4.21.5",
 ]
 extras = {
     "libcst": "libcst >= 0.2.5",
diff --git a/packages/google-cloud-automl/testing/constraints-3.7.txt b/packages/google-cloud-automl/testing/constraints-3.7.txt
index 5639db4cea9f..5ebdbc8e7448 100644
--- a/packages/google-cloud-automl/testing/constraints-3.7.txt
+++ b/packages/google-cloud-automl/testing/constraints-3.7.txt
@@ -10,4 +10,4 @@ proto-plus==1.22.0
 libcst==0.2.5
 pandas==1.0.5
 google-cloud-storage==1.18.0
-protobuf==3.20.2
\ No newline at end of file
+protobuf==3.19.5
\ No newline at end of file