diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index 5f46415394..4296316b5c 100644
--- a/src/backend/optimizer/path/indxpath.c
+++ b/src/backend/optimizer/path/indxpath.c
@@ -3966,7 +3966,7 @@ adjust_rowcompare_for_index(RowCompareExpr *clause,
 			break;				/* no good, volatile comparison value */
 
 		/*
-		 * The Var side can match any column of the index.
+		 * The Var side can match any key column of the index.
 		 */
 		for (i = 0; i < index->nkeycolumns; i++)
 		{
@@ -3978,7 +3978,7 @@ adjust_rowcompare_for_index(RowCompareExpr *clause,
 
 				break;
 		}
-		if (i >= index->ncolumns)
+		if (i >= index->nkeycolumns)
 			break;				/* no match found */
 
 		/* Add column number to returned list */
diff --git a/src/test/regress/expected/index_including.out b/src/test/regress/expected/index_including.out
index 16b4be34de..f86e5953fa 100644
--- a/src/test/regress/expected/index_including.out
+++ b/src/test/regress/expected/index_including.out
@@ -127,6 +127,23 @@ INSERT INTO tbl SELECT 1, NULL, 3*x, box('4,4,4,4') FROM generate_series(1,10) A
 ERROR:  null value in column "c2" violates not-null constraint
 DETAIL:  Failing row contains (1, null, 3, (4,4),(4,4)).
 INSERT INTO tbl SELECT x, 2*x, NULL, NULL FROM generate_series(1,10) AS x;
+explain (costs off)
+select * from tbl where (c1,c2,c3) < (2,5,1);
+                   QUERY PLAN                   
+------------------------------------------------
+ Bitmap Heap Scan on tbl
+   Filter: (ROW(c1, c2, c3) < ROW(2, 5, 1))
+   ->  Bitmap Index Scan on covering
+         Index Cond: (ROW(c1, c2) <= ROW(2, 5))
+(4 rows)
+
+select * from tbl where (c1,c2,c3) < (2,5,1);
+ c1 | c2 | c3 | c4 
+----+----+----+----
+  1 |  2 |    | 
+  2 |  4 |    | 
+(2 rows)
+
 DROP TABLE tbl;
 CREATE TABLE tbl (c1 int,c2 int, c3 int, c4 box,
 				UNIQUE(c1,c2) INCLUDE(c3,c4));
diff --git a/src/test/regress/sql/index_including.sql b/src/test/regress/sql/index_including.sql
index ef5fd882f5..2c6dd6211e 100644
--- a/src/test/regress/sql/index_including.sql
+++ b/src/test/regress/sql/index_including.sql
@@ -73,6 +73,9 @@ SELECT pg_get_constraintdef(oid), conname, conkey FROM pg_constraint WHERE conre
 INSERT INTO tbl SELECT 1, 2, 3*x, box('4,4,4,4') FROM generate_series(1,10) AS x;
 INSERT INTO tbl SELECT 1, NULL, 3*x, box('4,4,4,4') FROM generate_series(1,10) AS x;
 INSERT INTO tbl SELECT x, 2*x, NULL, NULL FROM generate_series(1,10) AS x;
+explain (costs off)
+select * from tbl where (c1,c2,c3) < (2,5,1);
+select * from tbl where (c1,c2,c3) < (2,5,1);
 DROP TABLE tbl;
 
 CREATE TABLE tbl (c1 int,c2 int, c3 int, c4 box,