diff --git a/pkg/addr/fmt.go b/pkg/addr/fmt.go
index 12b094d23f..ed9b2d9de1 100644
--- a/pkg/addr/fmt.go
+++ b/pkg/addr/fmt.go
@@ -65,7 +65,7 @@ func ParseFormattedAS(as string, opts ...FormatOption) (AS, error) {
 		}
 		as = trimmed
 	}
-	return ParseASSep(as, o.separator)
+	return parseAS(as, o.separator)
 }
 
 // FormatIA formats the ISD-AS.
diff --git a/private/path/fabridquery/parser.go b/private/path/fabridquery/parser.go
index 358ffd4a21..954adfd51b 100644
--- a/private/path/fabridquery/parser.go
+++ b/private/path/fabridquery/parser.go
@@ -176,7 +176,7 @@ func (l *pathpolicyConstraintsListener) ExitWildcardAS(c *pathpolicyconstraints.
 
 // ExitLegacyAS is called when exiting the LegacyAS production.
 func (l *pathpolicyConstraintsListener) ExitLegacyAS(c *pathpolicyconstraints.LegacyASContext) {
-	as, err := addr.ParseASSep(c.GetText()[1:], "_")
+	as, err := addr.ParseFormattedAS(c.GetText()[1:], addr.WithSeparator("_"))
 	if err != nil {
 		c.SetException(antlr.NewFailedPredicateException(c.GetParser(), c.GetText(), err.Error()))
 	}
@@ -186,7 +186,7 @@ func (l *pathpolicyConstraintsListener) ExitLegacyAS(c *pathpolicyconstraints.Le
 
 // ExitAS is called when exiting the AS production.
 func (l *pathpolicyConstraintsListener) ExitAS(c *pathpolicyconstraints.ASContext) {
-	as, err := addr.ParseASSep(c.GetText()[1:], "_")
+	as, err := addr.ParseFormattedAS(c.GetText()[1:], addr.WithSeparator("_"))
 	if err != nil {
 		c.SetException(antlr.NewFailedPredicateException(c.GetParser(), c.GetText(), err.Error()))
 	}