diff --git a/tuf/signed/errors.go b/tuf/signed/errors.go
index c042e60685..6cddcf2ba4 100644
--- a/tuf/signed/errors.go
+++ b/tuf/signed/errors.go
@@ -8,11 +8,10 @@ import (
 // metadata
 type ErrInsufficientSignatures struct {
 	Name string
-	Err  error
 }
 
 func (e ErrInsufficientSignatures) Error() string {
-	return fmt.Sprintf("tuf: insufficient signatures for %s: %s", e.Name, e.Err)
+	return fmt.Sprintf("tuf: insufficient signatures: %s", e.Name)
 }
 
 // ErrExpired indicates a piece of metadata has expired
diff --git a/tuf/signed/sign.go b/tuf/signed/sign.go
index 99987a2fb5..48a6efd7f0 100644
--- a/tuf/signed/sign.go
+++ b/tuf/signed/sign.go
@@ -68,8 +68,9 @@ func Sign(service CryptoService, s *data.Signed, keys ...data.PublicKey) error {
 	}
 	if len(signatures) < 1 {
 		return ErrInsufficientSignatures{
-			Name: fmt.Sprintf("Cryptoservice failed to produce any signatures for keys with IDs: %v", keyIDs),
-			Err:  nil,
+			Name: fmt.Sprintf(
+				"Cryptoservice failed to produce any signatures for keys with IDs: %v",
+				keyIDs),
 		}
 	}
 	for _, sig := range s.Signatures {