diff --git a/Libraries/LibC/getopt.h b/Libraries/LibC/getopt.h
index 5c422d414a..0aaddf2820 100644
--- a/Libraries/LibC/getopt.h
+++ b/Libraries/LibC/getopt.h
@@ -26,6 +26,8 @@
 
 #pragma once
 
+#include <sys/cdefs.h>
+
 __BEGIN_DECLS
 
 #define no_argument 0