1 files changed, 1 insertions, 0 deletions
diff --git a/src/io.c b/src/io.c
index 6616e88..a4dd962 100644
--- a/src/io.c
+++ b/src/io.c
@@ -13,6 +13,7 @@
 #include <limits.h>
 #include <stdarg.h>
 #include <stdbool.h>
+#include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>