diff --git a/lib/krb5/krb5.h b/lib/krb5/krb5.h
index 0c6656f14..dfc40a8d1 100644
--- a/lib/krb5/krb5.h
+++ b/lib/krb5/krb5.h
@@ -416,6 +416,7 @@ typedef struct krb5_context_data {
     char error_buf[256];
     krb5_addresses *ignore_addresses;
     char *default_cc_name;
+    int pkinit_win2k_compatible;
 } krb5_context_data;
 
 typedef struct krb5_ticket {