diff --git a/src/backend/parser/parse_node.c b/src/backend/parser/parse_node.c
index 59f1245fd6b..50ec98d211e 100644
--- a/src/backend/parser/parse_node.c
+++ b/src/backend/parser/parse_node.c
@@ -270,6 +270,18 @@ transformArraySubscripts(ParseState *pstate,
 	if (!OidIsValid(elementType))
 		elementType = transformArrayType(arrayType);
 
+	/*
+	 * We treat int2vector and oidvector as though they were domains over
+	 * int2[] and oid[].  This is needed because array slicing could create an
+	 * array that doesn't satisfy the dimensionality constraints of the
+	 * xxxvector type; so we want the result of a slice operation to be
+	 * considered to be of the more general type.
+	 */
+	if (arrayType == INT2VECTOROID)
+		arrayType = INT2ARRAYOID;
+	else if (arrayType == OIDVECTOROID)
+		arrayType = OIDARRAYOID;
+
 	/*
 	 * A list containing only single subscripts refers to a single array
 	 * element.  If any of the items are double subscripts (lower:upper), then
diff --git a/src/include/catalog/pg_type.h b/src/include/catalog/pg_type.h
index 3a10da25c37..1d130e83294 100644
--- a/src/include/catalog/pg_type.h
+++ b/src/include/catalog/pg_type.h
@@ -426,6 +426,7 @@ DATA(insert OID = 1001 (  _bytea	 PGNSP PGUID -1 f b A f t \054 0	17 0 array_in
 DATA(insert OID = 1002 (  _char		 PGNSP PGUID -1 f b A f t \054 0	18 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));
 DATA(insert OID = 1003 (  _name		 PGNSP PGUID -1 f b A f t \054 0	19 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));
 DATA(insert OID = 1005 (  _int2		 PGNSP PGUID -1 f b A f t \054 0	21 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));
+#define INT2ARRAYOID		1005
 DATA(insert OID = 1006 (  _int2vector PGNSP PGUID -1 f b A f t \054 0	22 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));
 DATA(insert OID = 1007 (  _int4		 PGNSP PGUID -1 f b A f t \054 0	23 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));
 #define INT4ARRAYOID		1007
@@ -433,6 +434,7 @@ DATA(insert OID = 1008 (  _regproc	 PGNSP PGUID -1 f b A f t \054 0	24 0 array_i
 DATA(insert OID = 1009 (  _text		 PGNSP PGUID -1 f b A f t \054 0	25 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));
 #define TEXTARRAYOID		1009
 DATA(insert OID = 1028 (  _oid		 PGNSP PGUID -1 f b A f t \054 0	26 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));
+#define OIDARRAYOID			1028
 DATA(insert OID = 1010 (  _tid		 PGNSP PGUID -1 f b A f t \054 0	27 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));
 DATA(insert OID = 1011 (  _xid		 PGNSP PGUID -1 f b A f t \054 0	28 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));
 DATA(insert OID = 1012 (  _cid		 PGNSP PGUID -1 f b A f t \054 0	29 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));