diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6cdd457..93c6009 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,12 @@
 # Changelog
 
+## [1.4.3](https://github.com/googleapis/python-debugger-client/compare/v1.4.2...v1.4.3) (2022-10-07)
+
+
+### Bug Fixes
+
+* **deps:** Allow protobuf 3.19.5 ([#133](https://github.com/googleapis/python-debugger-client/issues/133)) ([9f5ea8c](https://github.com/googleapis/python-debugger-client/commit/9f5ea8cafb8f9f5d39e827927b75bc076cba2504))
+
 ## [1.4.2](https://github.com/googleapis/python-debugger-client/compare/v1.4.1...v1.4.2) (2022-10-03)
 
 
diff --git a/setup.py b/setup.py
index c857eca..9ea2591 100644
--- a/setup.py
+++ b/setup.py
@@ -21,13 +21,13 @@
 
 name = "google-cloud-debugger-client"
 description = "Cloud Debugger API client library"
-version = "1.4.2"
+version = "1.4.3"
 release_status = "Development Status :: 5 - Production/Stable"
 url = "https://github.com/googleapis/python-debugger-client"
 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",
     "google-cloud-source-context >= 1.0.0, <2.0.0dev",
 ]
 
diff --git a/testing/constraints-3.7.txt b/testing/constraints-3.7.txt
index b08e445..2f80e0e 100644
--- a/testing/constraints-3.7.txt
+++ b/testing/constraints-3.7.txt
@@ -7,4 +7,4 @@
 google-api-core==1.32.0
 proto-plus==1.22.0
 google-cloud-source-context==1.0.0
-protobuf==3.20.2
+protobuf==3.19.5