diff --git a/tests/regression/issue_494/oneof_size.cc b/tests/regression/issue_494/oneof_size.cc
index 493166c..608fd91 100644
--- a/tests/regression/issue_494/oneof_size.cc
+++ b/tests/regression/issue_494/oneof_size.cc
@@ -1,7 +1,7 @@
 #include "oneof.pb.h"
 #include "unittests.h"
 
-int main()
+extern "C" int main()
 {
     int status = 0;