diff --git a/promql/parse.go b/promql/parse.go
index 03494662d..fcacb04a4 100644
--- a/promql/parse.go
+++ b/promql/parse.go
@@ -350,37 +350,6 @@ func (p *parser) newBinaryExpression(lhs Node, op Item, modifiers Node, rhs Node
 	ret.RHS = rhs.(Expr)
 	ret.Op = op.Typ
 
-	// opRange returns the PositionRange of the operator part of the BinaryExpr.
-	// This is made a function instead of a variable, so it is lazily evaluated on demand.
-	opRange := func() (r PositionRange) {
-		// Remove whitespace at the beginning and end of the range.
-		for r.Start = lhs.PositionRange().End; isSpace(rune(p.lex.input[r.Start])); r.Start++ {
-		}
-		for r.End = rhs.PositionRange().Start - 1; isSpace(rune(p.lex.input[r.End])); r.End-- {
-		}
-		return
-	}
-
-	if ret.ReturnBool && !op.Typ.isComparisonOperator() {
-		p.failf(opRange(), "bool modifier can only be used on comparison operators")
-	}
-
-	if op.Typ.isComparisonOperator() && !ret.ReturnBool && ret.RHS.Type() == ValueTypeScalar && ret.LHS.Type() == ValueTypeScalar {
-		p.failf(opRange(), "comparisons between scalars must use BOOL modifier")
-	}
-
-	if op.Typ.isSetOperator() && ret.VectorMatching.Card == CardOneToOne {
-		ret.VectorMatching.Card = CardManyToMany
-	}
-
-	for _, l1 := range ret.VectorMatching.MatchingLabels {
-		for _, l2 := range ret.VectorMatching.Include {
-			if l1 == l2 && ret.VectorMatching.On {
-				p.failf(opRange(), "label %q must not occur in ON and GROUP clause at once", l1)
-			}
-		}
-	}
-
 	return ret
 }
 
@@ -524,6 +493,37 @@ func (p *parser) checkType(node Node) (typ ValueType) {
 		lt := p.checkType(n.LHS)
 		rt := p.checkType(n.RHS)
 
+		// opRange returns the PositionRange of the operator part of the BinaryExpr.
+		// This is made a function instead of a variable, so it is lazily evaluated on demand.
+		opRange := func() (r PositionRange) {
+			// Remove whitespace at the beginning and end of the range.
+			for r.Start = n.LHS.PositionRange().End; isSpace(rune(p.lex.input[r.Start])); r.Start++ {
+			}
+			for r.End = n.RHS.PositionRange().Start - 1; isSpace(rune(p.lex.input[r.End])); r.End-- {
+			}
+			return
+		}
+
+		if n.ReturnBool && !n.Op.isComparisonOperator() {
+			p.failf(opRange(), "bool modifier can only be used on comparison operators")
+		}
+
+		if n.Op.isComparisonOperator() && !n.ReturnBool && n.RHS.Type() == ValueTypeScalar && n.LHS.Type() == ValueTypeScalar {
+			p.failf(opRange(), "comparisons between scalars must use BOOL modifier")
+		}
+
+		if n.Op.isSetOperator() && n.VectorMatching.Card == CardOneToOne {
+			n.VectorMatching.Card = CardManyToMany
+		}
+
+		for _, l1 := range n.VectorMatching.MatchingLabels {
+			for _, l2 := range n.VectorMatching.Include {
+				if l1 == l2 && n.VectorMatching.On {
+					p.failf(opRange(), "label %q must not occur in ON and GROUP clause at once", l1)
+				}
+			}
+		}
+
 		if !n.Op.isOperator() {
 			p.failf(n.PositionRange(), "binary expression does not support operator %q", n.Op)
 		}
diff --git a/promql/parse_test.go b/promql/parse_test.go
index 9bd6e57df..7792a9b97 100644
--- a/promql/parse_test.go
+++ b/promql/parse_test.go
@@ -2121,6 +2121,10 @@ var testExpr = []struct {
 		input:  "e-+=/(0)",
 		fail:   true,
 		errMsg: `unexpected "="`,
+	}, {
+		input:  "a>b()",
+		fail:   true,
+		errMsg: `unknown function`,
 	},
 	// String quoting and escape sequence interpretation tests.
 	{