diff --git a/lib/stringbuf.c b/lib/stringbuf.c
index 57009b1cd..2f3415d7c 100644
--- a/lib/stringbuf.c
+++ b/lib/stringbuf.c
@@ -1,5 +1,6 @@
 #include <stdlib.h>
 #include <ctype.h>
+#include <string.h>
 #include "stringbuf.h"
 
 #define BUF_CHUNK 1024