diff --git a/Libraries/LibC/iconv.h b/Libraries/LibC/iconv.h
index 70831a2565..438868fd83 100644
--- a/Libraries/LibC/iconv.h
+++ b/Libraries/LibC/iconv.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <sys/cdefs.h>
+#include <stddef.h>
 
 __BEGIN_DECLS