diff --git a/promql/printer.go b/promql/printer.go
index 709d8cb980..2298ba857d 100644
--- a/promql/printer.go
+++ b/promql/printer.go
@@ -139,15 +139,15 @@ func (node *AggregateExpr) String() string {
 		aggrString += fmt.Sprintf("%s, ", node.Param)
 	}
 	aggrString += fmt.Sprintf("%s)", node.Expr)
-	if len(node.Grouping) > 0 {
-		var format string
-		if node.Without {
-			format = "%s WITHOUT (%s)"
-		} else {
-			format = "%s BY (%s)"
+
+	if node.Without {
+		aggrString = fmt.Sprintf("%s WITHOUT (%s)", aggrString, strings.Join(node.Grouping, ", "))
+	} else {
+		if len(node.Grouping) > 0 {
+			aggrString = fmt.Sprintf("%s BY (%s)", aggrString, strings.Join(node.Grouping, ", "))
 		}
-		aggrString = fmt.Sprintf(format, aggrString, strings.Join(node.Grouping, ", "))
 	}
+
 	return aggrString
 }
 
diff --git a/promql/printer_test.go b/promql/printer_test.go
index 9a828067cc..50c637987e 100644
--- a/promql/printer_test.go
+++ b/promql/printer_test.go
@@ -63,6 +63,9 @@ func TestExprString(t *testing.T) {
 		{
 			in: `sum(task:errors:rate10s{job="s"}) BY (code)`,
 		},
+		{
+			in: `sum(task:errors:rate10s{job="s"}) WITHOUT ()`,
+		},
 		{
 			in: `sum(task:errors:rate10s{job="s"}) WITHOUT (instance)`,
 		},