diff --git a/src/query/parser/promql/parse_test.go b/src/query/parser/promql/parse_test.go
index 2c33852b03..b533d79044 100644
--- a/src/query/parser/promql/parse_test.go
+++ b/src/query/parser/promql/parse_test.go
@@ -77,7 +77,7 @@ func TestInvalidOffset(t *testing.T) {
 	require.Error(t, err)
 }
 
-func TestUnary(t *testing.T) {
+func TestNegativeUnary(t *testing.T) {
 	q := "-up"
 	p, err := Parse(q, models.NewTagOptions())
 	require.NoError(t, err)
@@ -93,6 +93,18 @@ func TestUnary(t *testing.T) {
 	assert.Equal(t, edges[0].ChildID, parser.NodeID("1"))
 }
 
+func TestPositiveUnary(t *testing.T) {
+	q := "+up"
+	p, err := Parse(q, models.NewTagOptions())
+	require.NoError(t, err)
+	transforms, edges, err := p.DAG()
+	require.NoError(t, err)
+	assert.Len(t, transforms, 1) // "+" defaults to just a fetch operation
+	assert.Equal(t, transforms[0].Op.OpType(), functions.FetchType)
+	assert.Equal(t, transforms[0].ID, parser.NodeID("0"))
+	assert.Len(t, edges, 0)
+}
+
 func TestInvalidUnary(t *testing.T) {
 	q := "*up"
 	_, err := Parse(q, models.NewTagOptions())
diff --git a/src/query/parser/promql/types.go b/src/query/parser/promql/types.go
index 5b29c05707..f617497846 100644
--- a/src/query/parser/promql/types.go
+++ b/src/query/parser/promql/types.go
@@ -248,7 +248,6 @@ func NewFunctionExpr(
 		return p, true, err
 
 	default:
-		// TODO: handle other types.
 		return nil, false, fmt.Errorf("function not supported: %s", name)
 	}
 }