diff --git a/include/memory.h b/include/memory.h
index 54c6c6e..ad86636 100644
--- a/include/memory.h
+++ b/include/memory.h
@@ -9,7 +9,7 @@ char *why2_strdup(char *string);
 
 void *why2_fopen(char *name, char *modes);
 void *why2_fdopen(int file, char *modes);
-int why2_open(char *name, int flags, ...);
+int why2_open(char *name, int flags, unsigned int mode);
 void *why2_opendir(char *name);
 
 void why2_deallocate(void *pointer);