diff --git a/consensus/ubqhash/consensus.go b/consensus/ubqhash/consensus.go
index 66b0b0e523..2a28b10a50 100644
--- a/consensus/ubqhash/consensus.go
+++ b/consensus/ubqhash/consensus.go
@@ -83,13 +83,11 @@ type diffConfig struct {
 // codebase, inherently breaking if the engine is swapped out. Please put common
 // error types into the consensus package.
 var (
-	errLargeBlockTime    = errors.New("timestamp too big")
 	errZeroBlockTime     = errors.New("timestamp equals parent's")
 	errTooManyUncles     = errors.New("too many uncles")
 	errDuplicateUncle    = errors.New("duplicate uncle")
 	errUncleIsAncestor   = errors.New("uncle is ancestor")
 	errDanglingUncle     = errors.New("uncle's parent is not ancestor")
-	errNonceOutOfRange   = errors.New("nonce out of range")
 	errInvalidDifficulty = errors.New("non-positive difficulty")
 	errInvalidMixDigest  = errors.New("invalid mix digest")
 	errInvalidPoW        = errors.New("invalid proof-of-work")