diff --git a/src/add-ons/kernel/generic/mpu401/debug.c b/src/add-ons/kernel/generic/mpu401/debug.c
index 2807f8d19b..9d2187d0d9 100644
--- a/src/add-ons/kernel/generic/mpu401/debug.c
+++ b/src/add-ons/kernel/generic/mpu401/debug.c
@@ -30,6 +30,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <OS.h>
+#include <string.h>
 #include "debug.h"
 
 #define DRIVER_NAME "mpu401"