diff --git a/set_null.c b/set_default.c
index bc323ec..b2dd91d 100644
--- a/set_null.c
+++ b/set_default.c
@@ -1,10 +1,10 @@
 /*
- * ri_setnull -
+ * ri_setdefault -
  *
- * Common code for ON DELETE SET NULL and ON UPDATE SET NULL
+ * Common code for ON DELETE SET DEFAULT and ON UPDATE SET DEFAULT
  */
 static Datum
-ri_setnull(TriggerData *trigdata)
+ri_setdefault(TriggerData *trigdata)
 {
     const RI_ConstraintInfo *riinfo;
     Relation    fk_rel;
@@ -30,10 +30,10 @@ ri_setnull(TriggerData *trigdata)
         elog(ERROR, "SPI_connect failed");
 
     /*
-     * Fetch or prepare a saved plan for the set null operation (it's
-     * the same query for delete and update cases)
+     * Fetch or prepare a saved plan for the set default operation
+     * (it's the same query for delete and update cases)
      */
-    ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_SETNULL_DOUPDATE);
+    ri_BuildQueryKey(&qkey, riinfo, RI_PLAN_SETDEFAULT_DOUPDATE);
 
     if ((qplan = ri_FetchPreparedPlan(&qkey)) == NULL)
     {
@@ -44,12 +44,12 @@ ri_setnull(TriggerData *trigdata)
         char        paramname[16];
         const char *querysep;
         const char *qualsep;
-        const char *fk_only;
         Oid         queryoids[RI_MAX_NUMKEYS];
+        const char *fk_only;
 
         /* ----------
          * The query string built is
-         *  UPDATE [ONLY] <fktable> SET fkatt1 = NULL [, ...]
+         *  UPDATE [ONLY] <fktable> SET fkatt1 = DEFAULT [, ...]
          *          WHERE $1 = fkatt1 [AND ...]
          * The type id's for the $ parameters are those of the
          * corresponding PK attributes.
@@ -57,9 +57,9 @@ ri_setnull(TriggerData *trigdata)
          */
         initStringInfo(&querybuf);
         initStringInfo(&qualbuf);
+        quoteRelationName(fkrelname, fk_rel);
         fk_only = fk_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ?
             "" : "ONLY ";
-        quoteRelationName(fkrelname, fk_rel);
         appendStringInfo(&querybuf, "UPDATE %s%s SET",
                          fk_only, fkrelname);
         querysep = "";
@@ -72,9 +72,10 @@ ri_setnull(TriggerData *trigdata)
             quoteOneName(attname,
                          RIAttName(fk_rel, riinfo->fk_attnums[i]));
             appendStringInfo(&querybuf,
-                             "%s %s = NULL",
+                             "%s %s = DEFAULT",
                              querysep, attname);
             sprintf(paramname, "$%d", i + 1);
+            sprintf(paramname, "$%d", i + 1);
             ri_GenerateQual(&qualbuf, qualsep,
                             paramname, pk_type,
                             riinfo->pf_eq_oprs[i],
@@ -104,5 +105,20 @@ ri_setnull(TriggerData *trigdata)
 
     table_close(fk_rel, RowExclusiveLock);
 
-    return PointerGetDatum(NULL);
+    /*
+     * If we just deleted or updated the PK row whose key was equal to
+     * the FK columns' default values, and a referencing row exists in
+     * the FK table, we would have updated that row to the same values
+     * it already had --- and RI_FKey_fk_upd_check_required would
+     * hence believe no check is necessary.  So we need to do another
+     * lookup now and in case a reference still exists, abort the
+     * operation.  That is already implemented in the NO ACTION
+     * trigger, so just run it.  (This recheck is only needed in the
+     * SET DEFAULT case, since CASCADE would remove such rows in case
+     * of a DELETE operation or would change the FK key values in case
+     * of an UPDATE, while SET NULL is certain to result in rows that
+     * satisfy the FK constraint.)
+     */
+    return ri_restrict(trigdata, true);
 }
+