diff --git a/du3/program.c b/du3/program.c
index 26f30db..1b712d0 100644
--- a/du3/program.c
+++ b/du3/program.c
@@ -18,7 +18,7 @@ void print_stack(struct stack *s) {
 
 void push_stack(struct stack *s, float value) {
    if (s->size >= STACK_SIZE) {
-      printf("no input\n");
+      printf("full stack\n");
       exit(0);
    }
    s->values[s->size] = value;