diff --git a/tools/include/nolibc/stdlib.h b/tools/include/nolibc/stdlib.h
index bacfd35c5156..5be9d3c7435a 100644
--- a/tools/include/nolibc/stdlib.h
+++ b/tools/include/nolibc/stdlib.h
@@ -185,7 +185,7 @@ void *realloc(void *old_ptr, size_t new_size)
 	if (__builtin_expect(!ret, 0))
 		return NULL;
 
-	memcpy(ret, heap->user_p, heap->len);
+	memcpy(ret, heap->user_p, user_p_len);
 	munmap(heap, heap->len);
 	return ret;
 }