diff --git a/ba/ba4.cpp b/ba/ba4.cpp
index 04640aa0e..0bd5d2d62 100755
--- a/ba/ba4.cpp
+++ b/ba/ba4.cpp
@@ -27,7 +27,9 @@ int main(int argc,char** argv)
   case 5:
     rt = ba4600(argc,argv) ; break;
   default:
-    error_box(usage, argv[0]) ; break;
+    error_box(usage, argv[0]) ; 
+    exit(1);
+    break;
   }
   return rt;
 }