diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index c8bd66dd54..1982e736fb 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -540,8 +540,8 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 %type <list>	func_arg_list func_arg_list_opt
 %type <node>	func_arg_expr
 %type <list>	row explicit_row implicit_row type_list array_expr_list
-%type <node>	case_expr case_arg when_clause case_default
-%type <list>	when_clause_list
+%type <node>	case_expr case_arg case_default
+%type <list>	when_clause when_clause_list when_expr_list
 %type <node>	opt_search_clause opt_cycle_clause
 %type <ival>	sub_type opt_materialized
 %type <node>	NumericOnly
@@ -16292,25 +16292,38 @@ case_expr:	CASE case_arg when_clause_list case_default END_P
 
 when_clause_list:
 			/* There must be at least one */
-			when_clause								{ $$ = list_make1($1); }
-			| when_clause_list when_clause			{ $$ = lappend($1, $2); }
+			when_clause								{ $$ = $1; }
+			| when_clause_list when_clause			{ $$ = list_concat($1, $2); }
 		;
 
+case_default:
+			ELSE a_expr								{ $$ = $2; }
+			| /*EMPTY*/								{ $$ = NULL; }
+		;
+
+when_expr_list:
+			a_expr									{ $$ = list_make1((Expr *) $1); }
+			| when_expr_list ',' a_expr				{ $$ = lappend($1, (Expr *) $3); }
+			;
+
 when_clause:
-			WHEN a_expr THEN a_expr
+			WHEN when_expr_list THEN a_expr
 				{
-					CaseWhen   *w = makeNode(CaseWhen);
+					ListCell   *lc;
+					List	   *when_clause_list = NIL;
 
-					w->expr = (Expr *) $2;
-					w->result = (Expr *) $4;
-					w->location = @1;
-					$$ = (Node *) w;
-				}
-		;
+					foreach(lc, $2)
+					{
+						CaseWhen   *w = makeNode(CaseWhen);
 
-case_default:
-			ELSE a_expr								{ $$ = $2; }
-			| /*EMPTY*/								{ $$ = NULL; }
+						w->expr = (Expr *) lfirst(lc);
+						w->result = (Expr *) $4;
+						w->location = @1;
+						when_clause_list = lappend(when_clause_list, w);
+					}
+
+					$$ = when_clause_list;
+				}
 		;
 
 case_arg:	a_expr									{ $$ = $1; }
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index fabb5f7207..41022fa5f0 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -1604,6 +1604,7 @@ transformCaseExpr(ParseState *pstate, CaseExpr *c)
 	ListCell   *l;
 	Node	   *defresult;
 	Oid			ptype;
+	int			prev_location = 0;
 
 	/* transform the test expression, if any */
 	arg = transformExprRecurse(pstate, (Node *) c->arg);
@@ -1649,6 +1650,23 @@ transformCaseExpr(ParseState *pstate, CaseExpr *c)
 		Node	   *warg;
 
 		warg = (Node *) w->expr;
+
+		/*
+		 * Comma separated predicate lists are only allowed for simple case
+		 * statements and not searchec case statements per the SQL standard.
+		 * If the CaseExpr arg isn't set then this is a searched case, and if
+		 * the CaseWhen expression have the same location as the previous then
+		 * it was parsed as a predicate list.
+		 */
+		if (prev_location && w->location == prev_location && !placeholder)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("predicate list is only allowed in simple CASE statements"),
+					 parser_errposition(pstate,
+					 					exprLocation(warg))));
+		else
+			prev_location = w->location;
+
 		if (placeholder)
 		{
 			/* shorthand form was specified, so expand... */
diff --git a/src/test/regress/expected/case.out b/src/test/regress/expected/case.out
index f5136c17ab..11cde667b6 100644
--- a/src/test/regress/expected/case.out
+++ b/src/test/regress/expected/case.out
@@ -288,6 +288,31 @@ SELECT * FROM CASE_TBL WHERE NULLIF(1, null) = 2;
    One-Time Filter: false
 (2 rows)
 
+-- Test comma separated predicate list for simple CASE
+SELECT
+  CASE i
+    WHEN 1 THEN 'one'
+	WHEN 2 THEN 'two'
+	WHEN 3,4,5 THEN 'many'
+	WHEN 6,7 THEN 'error'
+	END
+FROM case_tbl;
+ case 
+------
+ one
+ two
+ many
+ many
+(4 rows)
+
+SELECT
+  CASE
+    WHEN 2 > 1, 3 > 1 THEN 'right'
+	WHEN 1 > 2 THEN 'wrong'
+    END;
+ERROR:  predicate list is only allowed in simple CASE statements
+LINE 3:     WHEN 2 > 1, 3 > 1 THEN 'right'
+                        ^
 --
 -- Examples of updates involving tables
 --
diff --git a/src/test/regress/sql/case.sql b/src/test/regress/sql/case.sql
index 83fe43be6b..5cfcbde1ae 100644
--- a/src/test/regress/sql/case.sql
+++ b/src/test/regress/sql/case.sql
@@ -148,6 +148,22 @@ SELECT * FROM CASE_TBL WHERE NULLIF(1, 1) IS NOT NULL;
 explain (costs off)
 SELECT * FROM CASE_TBL WHERE NULLIF(1, null) = 2;
 
+-- Test comma separated predicate list for simple CASE
+SELECT
+  CASE i
+    WHEN 1 THEN 'one'
+	WHEN 2 THEN 'two'
+	WHEN 3,4,5 THEN 'many'
+	WHEN 6,7 THEN 'error'
+	END
+FROM case_tbl;
+
+SELECT
+  CASE
+    WHEN 2 > 1, 3 > 1 THEN 'right'
+	WHEN 1 > 2 THEN 'wrong'
+    END;
+
 --
 -- Examples of updates involving tables
 --