diff --git a/.github/actions/install-external-tools/action.yml b/.github/actions/install-external-tools/action.yml
index 1357618ce350..6046fe2a004c 100644
--- a/.github/actions/install-external-tools/action.yml
+++ b/.github/actions/install-external-tools/action.yml
@@ -22,7 +22,7 @@ runs:
     - uses: ./.github/actions/set-up-staticcheck
       # We assume that the Go toolchain will be managed by the caller workflow so we don't set one
       # up here.
-    - run: ./.github/scripts/retry-command.sh go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
+    - run: ./.github/scripts/retry-command.sh go install google.golang.org/protobuf/cmd/protoc-gen-go@v1.34.2
       shell: bash
     - run: ./.github/scripts/retry-command.sh go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@v1.4.0
       shell: bash
diff --git a/tools/tools.sh b/tools/tools.sh
index 8a8dffa7dddb..6d3cbad51b18 100755
--- a/tools/tools.sh
+++ b/tools/tools.sh
@@ -45,7 +45,7 @@ install_external() {
     github.com/loggerhead/enumer@latest
     github.com/rinchsan/gosimports/cmd/gosimports@latest
     golang.org/x/tools/cmd/goimports@latest
-    google.golang.org/protobuf/cmd/protoc-gen-go@latest
+    google.golang.org/protobuf/cmd/protoc-gen-go@v1.34.2
     google.golang.org/grpc/cmd/protoc-gen-go-grpc@v1.4.0
     gotest.tools/gotestsum@latest
     mvdan.cc/gofumpt@latest