diff --git a/include/System/string.h b/include/System/string.h
index 5ff2e8b..26e7d0c 100644
--- a/include/System/string.h
+++ b/include/System/string.h
@@ -18,6 +18,8 @@
 #ifndef LIBSYSTEM_STRING_H
 # define LIBSYSTEM_STRING_H
 
+# include <sys/types.h>
+
 
 /* String */
 /* types */