diff --git a/Source/shared/readobject.c b/Source/shared/readobject.c
index e28e025a6..f36d8cfee 100644
--- a/Source/shared/readobject.c
+++ b/Source/shared/readobject.c
@@ -1049,6 +1049,8 @@ int GetTokenId(char *token, int *opptr, int *num_opptr, int *num_outopptr){
 int GetObjectFrameTokenLoc(char *var, sv_object_frame *frame){
   int i;
 
+  assert(var!=NULL);
+  if(var == NULL)return -1;
   for(i = 0; i < frame->nsymbols; i++){
     int ii;
     tokendata *toki;