--- kdc/Makefile.am.orig	2016-12-20 14:23:06 UTC
+++ kdc/Makefile.am
@@ -47,10 +47,13 @@ libkdc_la_SOURCES = 		\
 	pkinit-ec.c		\
 	log.c			\
 	misc.c			\
-	kx509.c			\
+	$(libkdc_pkinit)	\
 	process.c		\
 	windc.c			\
 	rx.h
+if KX509
+libkdc_pkinit = kx509.c
+endif
 
 KDC_PROTOS = $(srcdir)/kdc-protos.h $(srcdir)/kdc-private.h