diff --git a/lib/krb5/krb5.h b/lib/krb5/krb5.h
index 98a338f5e..9e6e4844c 100644
--- a/lib/krb5/krb5.h
+++ b/lib/krb5/krb5.h
@@ -659,6 +659,7 @@ typedef struct krb5_krbhst_info {
 struct credentials; /* this is to keep the compiler happy */
 struct getargs;
 struct sockaddr;
+#include <stdarg.h>
 
 #include <krb5-protos.h>