diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 2f4e3f5cdfb..fa1777bbe42 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -1992,10 +1992,18 @@ transformArrayExpr(ParseState *pstate, A_ArrayExpr *a,
 
 			/*
 			 * Check for sub-array expressions, if we haven't already found
-			 * one.
+			 * one.  Note we don't accept domain-over-array as a sub-array,
+			 * nor int2vector nor oidvector; those have constraints that don't
+			 * map well to being treated as a sub-array.
 			 */
-			if (!newa->multidims && type_is_array(exprType(newe)))
-				newa->multidims = true;
+			if (!newa->multidims)
+			{
+				Oid			newetype = exprType(newe);
+
+				if (newetype != INT2VECTOROID && newetype != OIDVECTOROID &&
+					type_is_array(newetype))
+					newa->multidims = true;
+			}
 		}
 
 		newelems = lappend(newelems, newe);
diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c
index 57c12df0f73..2d03f967354 100644
--- a/src/backend/utils/adt/arrayfuncs.c
+++ b/src/backend/utils/adt/arrayfuncs.c
@@ -5800,9 +5800,14 @@ ArrayBuildStateAny *
 initArrayResultAny(Oid input_type, MemoryContext rcontext, bool subcontext)
 {
 	ArrayBuildStateAny *astate;
-	Oid			element_type = get_element_type(input_type);
 
-	if (OidIsValid(element_type))
+	/*
+	 * int2vector and oidvector will satisfy both get_element_type and
+	 * get_array_type.  We prefer to treat them as scalars, to be consistent
+	 * with get_promoted_array_type.  Hence, check get_array_type not
+	 * get_element_type.
+	 */
+	if (!OidIsValid(get_array_type(input_type)))
 	{
 		/* Array case */
 		ArrayBuildStateArr *arraystate;
@@ -5819,9 +5824,6 @@ initArrayResultAny(Oid input_type, MemoryContext rcontext, bool subcontext)
 		/* Scalar case */
 		ArrayBuildState *scalarstate;
 
-		/* Let's just check that we have a type that can be put into arrays */
-		Assert(OidIsValid(get_array_type(input_type)));
-
 		scalarstate = initArrayResult(input_type, rcontext, subcontext);
 		astate = (ArrayBuildStateAny *)
 			MemoryContextAlloc(scalarstate->mcontext,
diff --git a/src/test/regress/expected/arrays.out b/src/test/regress/expected/arrays.out
index 57a283dc591..42593c398ef 100644
--- a/src/test/regress/expected/arrays.out
+++ b/src/test/regress/expected/arrays.out
@@ -2301,6 +2301,132 @@ select array(select array['Hello', i::text] from generate_series(9,11) i);
  {{Hello,9},{Hello,10},{Hello,11}}
 (1 row)
 
+-- int2vector and oidvector should be treated as scalar types for this purpose
+select pg_typeof(array(select '11 22 33'::int2vector from generate_series(1,5)));
+  pg_typeof   
+--------------
+ int2vector[]
+(1 row)
+
+select array(select '11 22 33'::int2vector from generate_series(1,5));
+                          array                           
+----------------------------------------------------------
+ {"11 22 33","11 22 33","11 22 33","11 22 33","11 22 33"}
+(1 row)
+
+select unnest(array(select '11 22 33'::int2vector from generate_series(1,5)));
+  unnest  
+----------
+ 11 22 33
+ 11 22 33
+ 11 22 33
+ 11 22 33
+ 11 22 33
+(5 rows)
+
+select pg_typeof(array(select '11 22 33'::oidvector from generate_series(1,5)));
+  pg_typeof  
+-------------
+ oidvector[]
+(1 row)
+
+select array(select '11 22 33'::oidvector from generate_series(1,5));
+                          array                           
+----------------------------------------------------------
+ {"11 22 33","11 22 33","11 22 33","11 22 33","11 22 33"}
+(1 row)
+
+select unnest(array(select '11 22 33'::oidvector from generate_series(1,5)));
+  unnest  
+----------
+ 11 22 33
+ 11 22 33
+ 11 22 33
+ 11 22 33
+ 11 22 33
+(5 rows)
+
+-- array[] should do the same
+select pg_typeof(array['11 22 33'::int2vector]);
+  pg_typeof   
+--------------
+ int2vector[]
+(1 row)
+
+select array['11 22 33'::int2vector];
+    array     
+--------------
+ {"11 22 33"}
+(1 row)
+
+select pg_typeof(unnest(array['11 22 33'::int2vector]));
+ pg_typeof  
+------------
+ int2vector
+(1 row)
+
+select unnest(array['11 22 33'::int2vector]);
+  unnest  
+----------
+ 11 22 33
+(1 row)
+
+select pg_typeof(unnest('11 22 33'::int2vector));
+ pg_typeof 
+-----------
+ smallint
+ smallint
+ smallint
+(3 rows)
+
+select unnest('11 22 33'::int2vector);
+ unnest 
+--------
+     11
+     22
+     33
+(3 rows)
+
+select pg_typeof(array['11 22 33'::oidvector]);
+  pg_typeof  
+-------------
+ oidvector[]
+(1 row)
+
+select array['11 22 33'::oidvector];
+    array     
+--------------
+ {"11 22 33"}
+(1 row)
+
+select pg_typeof(unnest(array['11 22 33'::oidvector]));
+ pg_typeof 
+-----------
+ oidvector
+(1 row)
+
+select unnest(array['11 22 33'::oidvector]);
+  unnest  
+----------
+ 11 22 33
+(1 row)
+
+select pg_typeof(unnest('11 22 33'::oidvector));
+ pg_typeof 
+-----------
+ oid
+ oid
+ oid
+(3 rows)
+
+select unnest('11 22 33'::oidvector);
+ unnest 
+--------
+     11
+     22
+     33
+(3 rows)
+
 -- Insert/update on a column that is array of composite
 create temp table t1 (f1 int8_tbl[]);
 insert into t1 (f1[5].q1) values(42);
diff --git a/src/test/regress/sql/arrays.sql b/src/test/regress/sql/arrays.sql
index e414fa560db..025abe5fa61 100644
--- a/src/test/regress/sql/arrays.sql
+++ b/src/test/regress/sql/arrays.sql
@@ -682,6 +682,28 @@ select array_replace(array['AB',NULL,'CDE'],NULL,'12');
 select array(select array[i,i/2] from generate_series(1,5) i);
 select array(select array['Hello', i::text] from generate_series(9,11) i);
 
+-- int2vector and oidvector should be treated as scalar types for this purpose
+select pg_typeof(array(select '11 22 33'::int2vector from generate_series(1,5)));
+select array(select '11 22 33'::int2vector from generate_series(1,5));
+select unnest(array(select '11 22 33'::int2vector from generate_series(1,5)));
+select pg_typeof(array(select '11 22 33'::oidvector from generate_series(1,5)));
+select array(select '11 22 33'::oidvector from generate_series(1,5));
+select unnest(array(select '11 22 33'::oidvector from generate_series(1,5)));
+
+-- array[] should do the same
+select pg_typeof(array['11 22 33'::int2vector]);
+select array['11 22 33'::int2vector];
+select pg_typeof(unnest(array['11 22 33'::int2vector]));
+select unnest(array['11 22 33'::int2vector]);
+select pg_typeof(unnest('11 22 33'::int2vector));
+select unnest('11 22 33'::int2vector);
+select pg_typeof(array['11 22 33'::oidvector]);
+select array['11 22 33'::oidvector];
+select pg_typeof(unnest(array['11 22 33'::oidvector]));
+select unnest(array['11 22 33'::oidvector]);
+select pg_typeof(unnest('11 22 33'::oidvector));
+select unnest('11 22 33'::oidvector);
+
 -- Insert/update on a column that is array of composite
 
 create temp table t1 (f1 int8_tbl[]);