diff --git a/frontend/src/components/NewRunParametersV2.tsx b/frontend/src/components/NewRunParametersV2.tsx
index e864bd1e81d..1fced87abf7 100644
--- a/frontend/src/components/NewRunParametersV2.tsx
+++ b/frontend/src/components/NewRunParametersV2.tsx
@@ -70,8 +70,7 @@ const protoMap = new Map<string, string>([
 ]);
 
 function convertInput(paramStr: string, paramType: ParameterType_ParameterTypeEnum): any {
-  // TBD (jlyaoyuli): Currently, empty string is not allowed.
-  if (paramStr === '') {
+  if (paramStr === '' && paramType !== ParameterType_ParameterTypeEnum.STRING) {
     return undefined;
   }
   switch (paramType) {