diff --git a/tools/gce_setup/interop_test_runner.sh b/tools/gce_setup/interop_test_runner.sh
index 430ad09b8c6308ffd952b083171a8c5b2b64d9e0..7f0b5bab1a91c6d8d7cfd10fba5ff69737a2a2cb 100755
--- a/tools/gce_setup/interop_test_runner.sh
+++ b/tools/gce_setup/interop_test_runner.sh
@@ -37,7 +37,7 @@ main() {
   source grpc_docker.sh
   test_cases=(large_unary empty_unary ping_pong client_streaming server_streaming cancel_after_begin cancel_after_first_response)
   clients=(cxx java go ruby node python csharp_mono)
-  servers=(cxx java go ruby node python)
+  servers=(cxx java go ruby node python csharp_mono)
   for test_case in "${test_cases[@]}"
   do
     for client in "${clients[@]}"