1 files changed, 2 insertions, 0 deletions
diff --git a/utils.h b/utils.h
index 8aecde3..d7688c7 100644
--- a/utils.h
+++ b/utils.h
@@ -1,6 +1,8 @@
 #ifndef UTIL_H
 #define UTIL_H
 
+#include <stddef.h>
+
 #define ABS(x) ((x) >= 0 ? (x) : -(x))
 
 char *str_delete_at(const char *str, const int pos);