diff --git a/setup.py b/setup.py
index bb20cb754b..39be408a81 100644
--- a/setup.py
+++ b/setup.py
@@ -27,8 +27,8 @@
 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.*",
     "google-cloud-core >= 1.4.1, <3.0.0dev",
-    "proto-plus >= 1.20.5, <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 d25e547ee7..a872bcb9a4 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==1.4.1
-proto-plus==1.20.5
+proto-plus==1.22.0
 protobuf==3.19.0  # transitive from `google-api-core`