diff --git a/kdc/fast.c b/kdc/fast.c
index 42b4527cd..2fa9057d2 100644
--- a/kdc/fast.c
+++ b/kdc/fast.c
@@ -468,12 +468,14 @@ fast_unwrap_request(astgs_request_t r,
     krb5_boolean explicit_armor;
     krb5_error_code ret;
     krb5_ap_req ap_req;
-    KrbFastReq fastreq = {0};
+    KrbFastReq fastreq;
     const PA_DATA *pa;
     krb5_data data;
     size_t len;
     int i = 0;
 
+    memset(&fastreq, 0, sizeof(fastreq));
+
     pa = _kdc_find_padata(&r->req, &i, KRB5_PADATA_FX_FAST);
     if (pa == NULL) {
 	if (tgs_ac && r->fast_asserted) {