diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 1382b67..fa9a3f0 100644
*** a/src/backend/optimizer/plan/setrefs.c
--- b/src/backend/optimizer/plan/setrefs.c
*************** set_upper_references(PlannerInfo *root, 
*** 1744,1751 ****
  		TargetEntry *tle = (TargetEntry *) lfirst(l);
  		Node	   *newexpr;
  
! 		/* If it's a non-Var sort/group item, first try to match by sortref */
! 		if (tle->ressortgroupref != 0 && !IsA(tle->expr, Var))
  		{
  			newexpr = (Node *)
  				search_indexed_tlist_for_sortgroupref(tle->expr,
--- 1744,1751 ----
  		TargetEntry *tle = (TargetEntry *) lfirst(l);
  		Node	   *newexpr;
  
! 		/* If it's a sort/group item, first try to match by sortref */
! 		if (tle->ressortgroupref != 0)
  		{
  			newexpr = (Node *)
  				search_indexed_tlist_for_sortgroupref(tle->expr,
*************** search_indexed_tlist_for_non_var(Expr *n
*** 2113,2119 ****
  
  /*
   * search_indexed_tlist_for_sortgroupref --- find a sort/group expression
-  *		(which is assumed not to be just a Var)
   *
   * If a match is found, return a Var constructed to reference the tlist item.
   * If no match, return NULL.
--- 2113,2118 ----
diff --git a/src/test/regress/expected/groupingsets.out b/src/test/regress/expected/groupingsets.out
index fd618af..833d515 100644
*** a/src/test/regress/expected/groupingsets.out
--- b/src/test/regress/expected/groupingsets.out
*************** select a, d, grouping(a,b,c)
*** 360,365 ****
--- 360,394 ----
   2 | 2 |        2
  (4 rows)
  
+ -- check that distinct grouping columns are kept separate
+ -- even if they are equal()
+ explain (costs off)
+ select g as alias1, g as alias2
+   from generate_series(1,3) g
+  group by alias1, rollup(alias2);
+                    QUERY PLAN                   
+ ------------------------------------------------
+  GroupAggregate
+    Group Key: g, g
+    Group Key: g
+    ->  Sort
+          Sort Key: g
+          ->  Function Scan on generate_series g
+ (6 rows)
+ 
+ select g as alias1, g as alias2
+   from generate_series(1,3) g
+  group by alias1, rollup(alias2);
+  alias1 | alias2 
+ --------+--------
+       1 |      1
+       1 |       
+       2 |      2
+       2 |       
+       3 |      3
+       3 |       
+ (6 rows)
+ 
  -- simple rescan tests
  select a, b, sum(v.x)
    from (values (1),(2)) v(x), gstest_data(v.x)
diff --git a/src/test/regress/sql/groupingsets.sql b/src/test/regress/sql/groupingsets.sql
index 564ebc9..2b4ab69 100644
*** a/src/test/regress/sql/groupingsets.sql
--- b/src/test/regress/sql/groupingsets.sql
*************** select a, d, grouping(a,b,c)
*** 141,146 ****
--- 141,157 ----
    from gstest3
   group by grouping sets ((a,b), (a,c));
  
+ -- check that distinct grouping columns are kept separate
+ -- even if they are equal()
+ explain (costs off)
+ select g as alias1, g as alias2
+   from generate_series(1,3) g
+  group by alias1, rollup(alias2);
+ 
+ select g as alias1, g as alias2
+   from generate_series(1,3) g
+  group by alias1, rollup(alias2);
+ 
  -- simple rescan tests
  
  select a, b, sum(v.x)