diff --git a/lib/util/ttbl.c b/lib/util/ttbl.c
index 1790638..a78134b 100644
--- a/lib/util/ttbl.c
+++ b/lib/util/ttbl.c
@@ -26,6 +26,7 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 #include "hidrd/util/buf.h"
 #include "hidrd/util/ttbl.h"