Handle all cases properly
diff --git a/test/cpp/qps/qps_driver.cc b/test/cpp/qps/qps_driver.cc
index eceb510..d534846 100644
--- a/test/cpp/qps/qps_driver.cc
+++ b/test/cpp/qps/qps_driver.cc
@@ -132,6 +132,9 @@
       pareto->set_alpha(FLAGS_load_param_2);
       break;
     }
+    default:
+      GPR_ASSERT(false);
+      break;
   }
 
   ServerConfig server_config;