diff --git a/flag_bool_with_inverse.go b/flag_bool_with_inverse.go
index 272dd98fec..edbd2b7063 100644
--- a/flag_bool_with_inverse.go
+++ b/flag_bool_with_inverse.go
@@ -171,6 +171,9 @@ func (bif *BoolWithInverseFlag) String() string {
 	out := FlagStringer(bif)
 
 	i := strings.Index(out, "\t")
+	if i == -1 {
+		return out
+	}
 
 	prefix := "--"