diff --git a/expfmt/openmetrics_create.go b/expfmt/openmetrics_create.go
index 353c5e93..11c8ff4b 100644
--- a/expfmt/openmetrics_create.go
+++ b/expfmt/openmetrics_create.go
@@ -477,7 +477,7 @@ func writeOpenMetricsNameAndLabelPairs(
 	if name != "" {
 		// If the name does not pass the legacy validity check, we must put the
 		// metric name inside the braces, quoted.
-		if !model.IsValidLegacyMetricName(model.LabelValue(name)) {
+		if !model.IsValidLegacyMetricName(name) {
 			metricInsideBraces = true
 			err := w.WriteByte(separator)
 			written++
diff --git a/expfmt/text_create.go b/expfmt/text_create.go
index f9b8265a..4b86434b 100644
--- a/expfmt/text_create.go
+++ b/expfmt/text_create.go
@@ -354,7 +354,7 @@ func writeNameAndLabelPairs(
 	if name != "" {
 		// If the name does not pass the legacy validity check, we must put the
 		// metric name inside the braces.
-		if !model.IsValidLegacyMetricName(model.LabelValue(name)) {
+		if !model.IsValidLegacyMetricName(name) {
 			metricInsideBraces = true
 			err := w.WriteByte(separator)
 			written++
@@ -498,7 +498,7 @@ func writeInt(w enhancedWriter, i int64) (int, error) {
 // writeName writes a string as-is if it complies with the legacy naming
 // scheme, or escapes it in double quotes if not.
 func writeName(w enhancedWriter, name string) (int, error) {
-	if model.IsValidLegacyMetricName(model.LabelValue(name)) {
+	if model.IsValidLegacyMetricName(name) {
 		return w.WriteString(name)
 	}
 	var written int
diff --git a/model/metric.go b/model/metric.go
index eb865e5a..d0117b36 100644
--- a/model/metric.go
+++ b/model/metric.go
@@ -161,7 +161,7 @@ func (m Metric) FastFingerprint() Fingerprint {
 func IsValidMetricName(n LabelValue) bool {
 	switch NameValidationScheme {
 	case LegacyValidation:
-		return IsValidLegacyMetricName(n)
+		return IsValidLegacyMetricName(string(n))
 	case UTF8Validation:
 		if len(n) == 0 {
 			return false
@@ -176,7 +176,7 @@ func IsValidMetricName(n LabelValue) bool {
 // legacy validation scheme regardless of the value of NameValidationScheme.
 // This function, however, does not use MetricNameRE for the check but a much
 // faster hardcoded implementation.
-func IsValidLegacyMetricName(n LabelValue) bool {
+func IsValidLegacyMetricName(n string) bool {
 	if len(n) == 0 {
 		return false
 	}
@@ -208,7 +208,7 @@ func EscapeMetricFamily(v *dto.MetricFamily, scheme EscapingScheme) *dto.MetricF
 	}
 
 	// If the name is nil, copy as-is, don't try to escape.
-	if v.Name == nil || IsValidLegacyMetricName(LabelValue(v.GetName())) {
+	if v.Name == nil || IsValidLegacyMetricName(v.GetName()) {
 		out.Name = v.Name
 	} else {
 		out.Name = proto.String(EscapeName(v.GetName(), scheme))
@@ -230,7 +230,7 @@ func EscapeMetricFamily(v *dto.MetricFamily, scheme EscapingScheme) *dto.MetricF
 
 		for _, l := range m.Label {
 			if l.GetName() == MetricNameLabel {
-				if l.Value == nil || IsValidLegacyMetricName(LabelValue(l.GetValue())) {
+				if l.Value == nil || IsValidLegacyMetricName(l.GetValue()) {
 					escaped.Label = append(escaped.Label, l)
 					continue
 				}
@@ -240,7 +240,7 @@ func EscapeMetricFamily(v *dto.MetricFamily, scheme EscapingScheme) *dto.MetricF
 				})
 				continue
 			}
-			if l.Name == nil || IsValidLegacyMetricName(LabelValue(l.GetName())) {
+			if l.Name == nil || IsValidLegacyMetricName(l.GetName()) {
 				escaped.Label = append(escaped.Label, l)
 				continue
 			}
@@ -256,10 +256,10 @@ func EscapeMetricFamily(v *dto.MetricFamily, scheme EscapingScheme) *dto.MetricF
 
 func metricNeedsEscaping(m *dto.Metric) bool {
 	for _, l := range m.Label {
-		if l.GetName() == MetricNameLabel && !IsValidLegacyMetricName(LabelValue(l.GetValue())) {
+		if l.GetName() == MetricNameLabel && !IsValidLegacyMetricName(l.GetValue()) {
 			return true
 		}
-		if !IsValidLegacyMetricName(LabelValue(l.GetName())) {
+		if !IsValidLegacyMetricName(l.GetName()) {
 			return true
 		}
 	}
@@ -283,7 +283,7 @@ func EscapeName(name string, scheme EscapingScheme) string {
 	case NoEscaping:
 		return name
 	case UnderscoreEscaping:
-		if IsValidLegacyMetricName(LabelValue(name)) {
+		if IsValidLegacyMetricName(name) {
 			return name
 		}
 		for i, b := range name {
@@ -309,7 +309,7 @@ func EscapeName(name string, scheme EscapingScheme) string {
 		}
 		return escaped.String()
 	case ValueEncodingEscaping:
-		if IsValidLegacyMetricName(LabelValue(name)) {
+		if IsValidLegacyMetricName(name) {
 			return name
 		}
 		escaped.WriteString("U__")