diff --git a/consensus/byzantine_test.go b/consensus/byzantine_test.go
index f103beae..6be23c8b 100644
--- a/consensus/byzantine_test.go
+++ b/consensus/byzantine_test.go
@@ -9,7 +9,6 @@ import (
 
 	. "github.com/tendermint/go-common"
 	cfg "github.com/tendermint/go-config"
-	"github.com/tendermint/go-crypto"
 	"github.com/tendermint/go-events"
 	"github.com/tendermint/go-p2p"
 	"github.com/tendermint/tendermint/types"
@@ -259,7 +258,7 @@ func (privVal *ByzantinePrivValidator) SignVote(chainID string, vote *types.Vote
 	defer privVal.mtx.Unlock()
 
 	// Sign
-	vote.Signature = privVal.Sign(types.SignBytes(chainID, vote)).(crypto.SignatureEd25519)
+	vote.Signature = privVal.Sign(types.SignBytes(chainID, vote))
 	return nil
 }
 
@@ -268,7 +267,7 @@ func (privVal *ByzantinePrivValidator) SignProposal(chainID string, proposal *ty
 	defer privVal.mtx.Unlock()
 
 	// Sign
-	proposal.Signature = privVal.Sign(types.SignBytes(chainID, proposal)).(crypto.SignatureEd25519)
+	proposal.Signature = privVal.Sign(types.SignBytes(chainID, proposal))
 	return nil
 }
 
diff --git a/state/execution_test.go b/state/execution_test.go
index cbaab099..16a9a080 100644
--- a/state/execution_test.go
+++ b/state/execution_test.go
@@ -134,7 +134,7 @@ func signCommit(height, round int, hash []byte, header types.PartSetHeader) *typ
 	}
 
 	sig := privKey.Sign(types.SignBytes(chainID, vote))
-	vote.Signature = sig.(crypto.SignatureEd25519)
+	vote.Signature = sig
 	return vote
 }
 
diff --git a/types/priv_validator.go b/types/priv_validator.go
index e54bc4d5..c200dff3 100644
--- a/types/priv_validator.go
+++ b/types/priv_validator.go
@@ -174,7 +174,7 @@ func (privVal *PrivValidator) SignVote(chainID string, vote *Vote) error {
 	if err != nil {
 		return errors.New(Fmt("Error signing vote: %v", err))
 	}
-	vote.Signature = signature.(crypto.SignatureEd25519)
+	vote.Signature = signature
 	return nil
 }
 
@@ -185,7 +185,7 @@ func (privVal *PrivValidator) SignProposal(chainID string, proposal *Proposal) e
 	if err != nil {
 		return errors.New(Fmt("Error signing proposal: %v", err))
 	}
-	proposal.Signature = signature.(crypto.SignatureEd25519)
+	proposal.Signature = signature
 	return nil
 }
 
diff --git a/types/vote.go b/types/vote.go
index 2a30da0c..af4f60fc 100644
--- a/types/vote.go
+++ b/types/vote.go
@@ -47,13 +47,13 @@ func IsVoteTypeValid(type_ byte) bool {
 
 // Represents a prevote, precommit, or commit vote from validators for consensus.
 type Vote struct {
-	ValidatorAddress []byte                  `json:"validator_address"`
-	ValidatorIndex   int                     `json:"validator_index"`
-	Height           int                     `json:"height"`
-	Round            int                     `json:"round"`
-	Type             byte                    `json:"type"`
-	BlockID          BlockID                 `json:"block_id"` // zero if vote is nil.
-	Signature        crypto.SignatureEd25519 `json:"signature"`
+	ValidatorAddress []byte           `json:"validator_address"`
+	ValidatorIndex   int              `json:"validator_index"`
+	Height           int              `json:"height"`
+	Round            int              `json:"round"`
+	Type             byte             `json:"type"`
+	BlockID          BlockID          `json:"block_id"` // zero if vote is nil.
+	Signature        crypto.Signature `json:"signature"`
 }
 
 func (vote *Vote) WriteSignBytes(chainID string, w io.Writer, n *int, err *error) {
diff --git a/types/vote_set_test.go b/types/vote_set_test.go
index 48ccb0b1..500daadf 100644
--- a/types/vote_set_test.go
+++ b/types/vote_set_test.go
@@ -61,7 +61,7 @@ func withBlockPartsHeader(vote *Vote, blockPartsHeader PartSetHeader) *Vote {
 }
 
 func signAddVote(privVal *PrivValidator, vote *Vote, voteSet *VoteSet) (bool, error) {
-	vote.Signature = privVal.Sign(SignBytes(voteSet.ChainID(), vote)).(crypto.SignatureEd25519)
+	vote.Signature = privVal.Sign(SignBytes(voteSet.ChainID(), vote))
 	added, err := voteSet.AddVote(vote)
 	return added, err
 }