diff --git a/include/System.h b/include/System.h
index 38c3927..741bf51 100644
--- a/include/System.h
+++ b/include/System.h
@@ -9,5 +9,6 @@
 # include <appclient.h>
 # include <appserver.h>
 # include <event.h>
+# include <string.h>
 
 #endif /* !_SYSTEM_H */