diff --git a/libc/include/wait.h b/libc/include/wait.h
index d01b811..e375daa 100644
--- a/libc/include/wait.h
+++ b/libc/include/wait.h
@@ -1 +1,10 @@
+#pragma once
+
+/**
+ * @file wait.h
+ * @brief Historical alternative to `<sys/wait.h>`.
+ *
+ * New code should use `<sys/wait.h>` directly.
+ */
+
 #include <sys/wait.h>