diff --git a/kdc/fast.c b/kdc/fast.c
index 8043d0d65..eaeb9a543 100644
--- a/kdc/fast.c
+++ b/kdc/fast.c
@@ -844,8 +844,8 @@ _kdc_free_fast_state(KDCFastState *state)
 	PA_DATA *pa = &state->fast_state.val[i];
 
 	if (pa->padata_value.data)
-	    memset_s(pa->padata_value.data, 0,
-		     pa->padata_value.length, pa->padata_value.length);
+	    memset_s(pa->padata_value.data, pa->padata_value.length,
+		     0, pa->padata_value.length);
     }
     free_KDCFastState(state);
 }
diff --git a/kdc/krb5tgs.c b/kdc/krb5tgs.c
index a9c90b0e8..ad61a9fb1 100644
--- a/kdc/krb5tgs.c
+++ b/kdc/krb5tgs.c
@@ -2210,7 +2210,7 @@ out:
     }
     free_LastReq(&r->ek.last_req);
     if (r->et.key.keyvalue.data) {
-	memset_s(r->et.key.keyvalue.data, 0, r->et.key.keyvalue.length,
+	memset_s(r->et.key.keyvalue.data, r->et.key.keyvalue.length, 0,
 		 r->et.key.keyvalue.length);
     }
     free_EncryptionKey(&r->et.key);