diff --git a/internal/core/adt/feature.go b/internal/core/adt/feature.go
index bc2a32c..74926a6 100644
--- a/internal/core/adt/feature.go
+++ b/internal/core/adt/feature.go
@@ -116,7 +116,7 @@
 	i := r.StringToIndex(s)
 	t := StringLabel
 	switch {
-	case strings.HasPrefix(s, "#_"):
+	case strings.HasPrefix(s, "_#"):
 		t = HiddenDefinitionLabel
 	case strings.HasPrefix(s, "#"):
 		t = DefinitionLabel