diff --git a/tools/run_tests/helper_scripts/build_python.sh b/tools/run_tests/helper_scripts/build_python.sh
index f93c86a97ac..7542345f2ec 100755
--- a/tools/run_tests/helper_scripts/build_python.sh
+++ b/tools/run_tests/helper_scripts/build_python.sh
@@ -160,7 +160,7 @@ pip_install_dir() {
 case "$VENV" in
   *gevent*)
   # TODO(https://github.com/grpc/grpc/issues/15411) unpin this
-  $VENV_PYTHON -m pip install gevent==1.3.a2
+  $VENV_PYTHON -m pip install gevent==1.3.b1
   ;;
 esac