diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 0bef48e07b..58f0b01b09 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.254 2008/05/16 23:36:04 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.255 2008/05/19 04:14:24 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -4377,11 +4377,11 @@ ATAddForeignKeyConstraint(AlteredTableInfo *tab, Relation rel,
 			/*
 			 * Otherwise, look for an implicit cast from the FK type to the
 			 * opcintype, and if found, use the primary equality operator.
-			 * This is a bit tricky because opcintype might be a generic type
-			 * such as ANYARRAY, and so what we have to test is whether the
-			 * two actual column types can be concurrently cast to that type.
-			 * (Otherwise, we'd fail to reject combinations such as int[] and
-			 * point[].)
+			 * This is a bit tricky because opcintype might be a polymorphic
+			 * type such as ANYARRAY or ANYENUM; so what we have to test is
+			 * whether the two actual column types can be concurrently cast to
+			 * that type.  (Otherwise, we'd fail to reject combinations such
+			 * as int[] and point[].)
 			 */
 			Oid			input_typeids[2];
 			Oid			target_typeids[2];
diff --git a/src/backend/utils/adt/ri_triggers.c b/src/backend/utils/adt/ri_triggers.c
index 59f7e49795..7f564e09fa 100644
--- a/src/backend/utils/adt/ri_triggers.c
+++ b/src/backend/utils/adt/ri_triggers.c
@@ -15,7 +15,7 @@
  *
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/backend/utils/adt/ri_triggers.c,v 1.108 2008/05/12 20:02:02 alvherre Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/ri_triggers.c,v 1.109 2008/05/19 04:14:24 tgl Exp $
  *
  * ----------
  */
@@ -3938,8 +3938,12 @@ ri_HashCompareOp(Oid eq_opr, Oid typeid)
 			if (pathtype != COERCION_PATH_FUNC &&
 				pathtype != COERCION_PATH_RELABELTYPE)
 			{
-				/* If target is ANYARRAY, assume it's OK, else punt. */
-				if (lefttype != ANYARRAYOID)
+				/*
+				 * The declared input type of the eq_opr might be a
+				 * polymorphic type such as ANYARRAY or ANYENUM.  If so,
+				 * assume the coercion is valid; otherwise complain.
+				 */
+				if (!IsPolymorphicType(lefttype))
 					elog(ERROR, "no conversion function from %s to %s",
 						 format_type_be(typeid),
 						 format_type_be(lefttype));