diff --git a/model/textparse/interface.go b/model/textparse/interface.go
index 2e8c40e72..df01dbc34 100644
--- a/model/textparse/interface.go
+++ b/model/textparse/interface.go
@@ -71,8 +71,8 @@ type Parser interface {
 	// if the scrape protocol or metric type does not support created timestamps.
 	CreatedTimestamp() *int64
 
-	// Next advances the parser to the next sample. It returns false if no
-	// more samples were read or an error occurred.
+	// Next advances the parser to the next sample.
+	// It returns (EntryInvalid, io.EOF) if no samples were read.
 	Next() (Entry, error)
 }
 
diff --git a/model/textparse/openmetricsparse.go b/model/textparse/openmetricsparse.go
index ea92bc55f..b7ad1dd85 100644
--- a/model/textparse/openmetricsparse.go
+++ b/model/textparse/openmetricsparse.go
@@ -239,8 +239,8 @@ func (p *OpenMetricsParser) parseError(exp string, got token) error {
 	return fmt.Errorf("%s, got %q (%q) while parsing: %q", exp, p.l.b[p.l.start:e], got, p.l.b[p.start:e])
 }
 
-// Next advances the parser to the next sample. It returns false if no
-// more samples were read or an error occurred.
+// Next advances the parser to the next sample.
+// It returns (EntryInvalid, io.EOF) if no samples were read.
 func (p *OpenMetricsParser) Next() (Entry, error) {
 	var err error
 
diff --git a/model/textparse/promparse.go b/model/textparse/promparse.go
index 54b5306e6..a611f3aea 100644
--- a/model/textparse/promparse.go
+++ b/model/textparse/promparse.go
@@ -280,8 +280,8 @@ func (p *PromParser) parseError(exp string, got token) error {
 	return fmt.Errorf("%s, got %q (%q) while parsing: %q", exp, p.l.b[p.l.start:e], got, p.l.b[p.start:e])
 }
 
-// Next advances the parser to the next sample. It returns false if no
-// more samples were read or an error occurred.
+// Next advances the parser to the next sample.
+// It returns (EntryInvalid, io.EOF) if no samples were read.
 func (p *PromParser) Next() (Entry, error) {
 	var err error