diff --git a/stack.c b/stack.c
index a49bdd9..2375723 100644
--- a/stack.c
+++ b/stack.c
@@ -52,6 +52,9 @@ void clearStack(StackNode *stack)
         StackNode *next = stack->next;
         free(stack);
         stack = next;
+        stack->data = NULL;
+        stack->next = NULL;
+        stack->prev = NULL;
     }
 
     return NULL;