diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 89a609f..e0eeae0 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -13350,10 +13350,10 @@ SELECT xmlagg(x) FROM (SELECT x FROM test ORDER BY y DESC) AS tab;
        <function>GROUPING(<replaceable class="parameter">args...</replaceable>)</function>
       </entry>
       <entry>
-       <type>integer</type>
+       <type>bigint</type>
       </entry>
       <entry>
-       Integer bitmask indicating which arguments are not being included in the current
+       Bitmask indicating which arguments are not being included in the current
        grouping set
       </entry>
      </row>
diff --git a/src/backend/executor/execQual.c b/src/backend/executor/execQual.c
index d414e20..70e9c28 100644
--- a/src/backend/executor/execQual.c
+++ b/src/backend/executor/execQual.c
@@ -3034,10 +3034,10 @@ ExecEvalGroupingFuncExpr(GroupingFuncExprState *gstate,
 						 bool *isNull,
 						 ExprDoneCond *isDone)
 {
-	int result = 0;
-	int attnum = 0;
-	Bitmapset *grouped_cols = gstate->aggstate->grouped_cols;
-	ListCell *lc;
+	int64		result = 0;
+	int			attnum = 0;
+	Bitmapset  *grouped_cols = gstate->aggstate->grouped_cols;
+	ListCell   *lc;
 
 	if (isDone)
 		*isDone = ExprSingleResult;
@@ -3054,7 +3054,7 @@ ExecEvalGroupingFuncExpr(GroupingFuncExprState *gstate,
 			result = result | 1;
 	}
 
-	return (Datum) result;
+	return Int64GetDatum(result);
 }
 
 /* ----------------------------------------------------------------
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index 4176393..baa3303 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/src/backend/nodes/nodeFuncs.c
@@ -55,7 +55,7 @@ exprType(const Node *expr)
 			type = ((const Aggref *) expr)->aggtype;
 			break;
 		case T_GroupingFunc:
-			type = INT4OID;
+			type = INT8OID;
 			break;
 		case T_WindowFunc:
 			type = ((const WindowFunc *) expr)->wintype;
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index 1e3f2e0..8119af5 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -238,10 +238,10 @@ transformGroupingFunc(ParseState *pstate, GroupingFunc *p)
 	List	   *result_list = NIL;
 	GroupingFunc *result = makeNode(GroupingFunc);
 
-	if (list_length(args) > 31)
+	if (list_length(args) > 63)
 		ereport(ERROR,
 				(errcode(ERRCODE_TOO_MANY_ARGUMENTS),
-				 errmsg("GROUPING must have fewer than 32 arguments"),
+				 errmsg("GROUPING must have fewer than 64 arguments"),
 				 parser_errposition(pstate, p->location)));
 
 	foreach(lc, args)