diff --git a/ev_helpers.h b/ev_helpers.h
index 9298f48..773a1ed 100644
--- a/ev_helpers.h
+++ b/ev_helpers.h
@@ -33,6 +33,7 @@ evstring_readFile(
   if(fopen_s(&f,filePath,"rb")) return EV_INVALID(evstring);
 #else
   f = fopen(filePath, "rb");
+  if(f == NULL) return EV_INVALID(evstring);
 #endif
 
   fseek(f, 0, SEEK_END);