diff --git a/fmt_test.go b/fmt_test.go
index 1e3c060..99d945f 100644
--- a/fmt_test.go
+++ b/fmt_test.go
@@ -485,7 +485,7 @@ type adapted struct {
 	err error
 }
 
-func (e adapted) Error() string { return string(e.msg) }
+func (e adapted) Error() string { return e.msg }
 
 func (e adapted) Format(s fmt.State, verb rune) {
 	xerrors.FormatError(e, s, verb)