diff --git a/kdc/Makefile.am b/kdc/Makefile.am
index ec359c6a4..63233fb19 100644
--- a/kdc/Makefile.am
+++ b/kdc/Makefile.am
@@ -39,6 +39,7 @@ libkdc_la_SOURCES = 		\
 	524.c			\
 	kerberos4.c		\
 	kaserver.c		\
+	kx509.c			\
 	process.c		\
 	rx.h