diff --git a/libc/include/sys/quota.h b/libc/include/sys/quota.h
index 157c2d9..f8faee7 100644
--- a/libc/include/sys/quota.h
+++ b/libc/include/sys/quota.h
@@ -26,8 +26,12 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _SYS_QUOTA_H_
-#define _SYS_QUOTA_H_
+#pragma once
+
+/**
+ * @file sys/quota.h
+ * @brief The quotactl() function.
+ */
 
 #include <sys/cdefs.h>
 
@@ -40,8 +44,13 @@
 
 __BEGIN_DECLS
 
+/**
+ * [quotactl(2)](http://man7.org/linux/man-pages/man2/quotactl.2.html) manipulates disk quotas.
+ *
+ * Returns 0 on success, and returns -1 and sets `errno` on failure.
+ *
+ * Available since API level 26.
+ */
 int quotactl(int __cmd, const char* __special, int __id, char* __addr) __INTRODUCED_IN(26);
 
 __END_DECLS
-
-#endif