diff --git a/kerberos5/lib/libhdb/Makefile b/kerberos5/lib/libhdb/Makefile
index 66e0a67475ff..9134fb5180a6 100644
--- a/kerberos5/lib/libhdb/Makefile
+++ b/kerberos5/lib/libhdb/Makefile
@@ -96,6 +96,9 @@ ${GEN}: hdb.asn1
 .hx.h:
 	${CP} ${.IMPSRC} ${.TARGET}
 
+# This makefile generates a lot of its headers
+# so tell bsd.sys.mk not to try and stage them before they are built.
+# Note: this is rare
 NO_BEFOREBUILD_INCLUDES=
 
 .include <bsd.lib.mk>