diff --git a/cv8/program.c b/cv8/program.c
index 424b78e..f1592da 100644
--- a/cv8/program.c
+++ b/cv8/program.c
@@ -55,6 +55,8 @@ struct binary* productAppend(struct binary* myTree, char* product){
             break;
         if(itrNode->right->value[0] != '*')
             itrNode = (!productAppend(itrNode->right, product)) ? itrNode : productAppend(itrNode->right, product);
+        if(!itrNode)
+        	return NULL;
     }
 
     if(!endingFound && !itrNode->left) {