diff --git a/libc/include/sys/param.h b/libc/include/sys/param.h
index 4a83e9d..5cde4b7 100644
--- a/libc/include/sys/param.h
+++ b/libc/include/sys/param.h
@@ -33,6 +33,7 @@
  * @brief Various macros.
  */
 
+#include <endian.h>
 #include <limits.h>
 #include <linux/param.h>
 #include <sys/cdefs.h>