diff --git a/promql/parser/parse.go b/promql/parser/parse.go
index 5cf85ea350..0416720eb1 100644
--- a/promql/parser/parse.go
+++ b/promql/parser/parse.go
@@ -82,6 +82,7 @@ func NewParser(input string, opts ...Opt) *parser { //nolint:revive // unexporte
 	p.injecting = false
 	p.parseErrors = nil
 	p.generatedParserResult = nil
+	p.lastClosing = posrange.Pos(0)
 
 	// Clear lexer struct before reusing.
 	p.lex = Lexer{
diff --git a/promql/parser/parse_test.go b/promql/parser/parse_test.go
index 129701b010..24c920fe29 100644
--- a/promql/parser/parse_test.go
+++ b/promql/parser/parse_test.go
@@ -4823,6 +4823,11 @@ var testExpr = []struct {
 			PosRange: posrange.PositionRange{Start: 0, End: 20},
 		},
 	},
+	{
+		input:  "sum(rate(",
+		fail:   true,
+		errMsg: "unclosed left parenthesis",
+	},
 	{
 		input:  "foo[5s x 5s]",
 		fail:   true,