diff --git a/src/compiler/objective_c_plugin.cc b/src/compiler/objective_c_plugin.cc
index 92b9c828fb680273dc03a7e243e4f4bae6839deb..aeaf743c6321fa1ce6c93d0a961ae049d70c8c4d 100644
--- a/src/compiler/objective_c_plugin.cc
+++ b/src/compiler/objective_c_plugin.cc
@@ -63,7 +63,7 @@ class ObjectiveCGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
 
     // Simple parameter parsing as we have only one parameter.
     // TODO(mxyan): Complete parameter parsing.
-    bool dash_as_separator = (0 == parameter.compare("--filename-dash-as-separator"));
+    bool dash_as_separator = (0 == parameter.compare("filename-dash-as-separator"));
     if (dash_as_separator) {
       file_name = google::protobuf::compiler::objectivec::FilePath(file);
     } else {