diff --git a/setup.py b/setup.py
index f879347f8..46a59dc82 100644
--- a/setup.py
+++ b/setup.py
@@ -34,8 +34,8 @@
     "google-cloud-audit-log >= 0.1.0, < 1.0.0dev",
     "google-cloud-core >= 2.0.0, <3.0.0dev",
     "grpc-google-iam-v1 >=0.12.4, <1.0.0dev",
-    "proto-plus >= 1.15.0, <2.0.0dev",
-    "protobuf >= 3.19.0, <4.0.0dev",
+    "proto-plus >= 1.22.0, <2.0.0dev",
+    "protobuf >= 3.19.0, <5.0.0dev",
 ]
 extras = {}
 
diff --git a/testing/constraints-3.7.txt b/testing/constraints-3.7.txt
index 07d97d4a8..2b42f18bc 100644
--- a/testing/constraints-3.7.txt
+++ b/testing/constraints-3.7.txt
@@ -7,5 +7,5 @@
 # Then this file should have foo==1.14.0
 google-api-core==1.32.0
 google-cloud-core==2.0.0
-proto-plus==1.15.0
+proto-plus==1.22.0
 protobuf==3.19.0