diff --git a/lib/connect.c b/lib/connect.c
index 791aadd5..ad3bb1d0 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -16,6 +16,8 @@ Contributors:
 
 #include "config.h"
 
+#include <string.h>
+
 #include "mosquitto.h"
 #include "mosquitto_internal.h"
 #include "logging_mosq.h"