diff --git a/types/errors.go b/types/errors.go
index da4519725..1115d3937 100644
--- a/types/errors.go
+++ b/types/errors.go
@@ -108,9 +108,6 @@ func ErrInsufficientCoins(msg string) Error {
 func ErrInvalidCoins(msg string) Error {
 	return newError(CodeInvalidCoins, msg)
 }
-func ErrInvalidCoins(coins Coins) Error {
-	return newError(CodeInvalidCoins, coins.String())
-}
 
 //----------------------------------------
 // Error & sdkError
diff --git a/x/stake/handler.go b/x/stake/handler.go
index 091268b44..bc3f4b9d7 100644
--- a/x/stake/handler.go
+++ b/x/stake/handler.go
@@ -64,7 +64,7 @@ func NewHandler(k Keeper, ck bank.CoinKeeper) sdk.Handler {
 		case MsgUnbond:
 			return k.handleMsgUnbond(ctx, msg)
 		default:
-			return sdk.ErrTxParse("invalid message parse in staking module").Result()
+			return sdk.ErrTxDecode("invalid message parse in staking module").Result()
 		}
 	}
 }
diff --git a/x/stake/keeper_test.go b/x/stake/keeper_test.go
index 911b7036c..9a122bb0f 100644
--- a/x/stake/keeper_test.go
+++ b/x/stake/keeper_test.go
@@ -47,14 +47,13 @@ func TestUpdateVotingPower(t *testing.T) {
 	// initialize some candidates into the state
 	amts := []int64{400, 200, 100, 10, 1}
 	candidates := make([]Candidate, 5)
-	for i := 0; i < len(5); i++ {
+	for i := 0; i < 5; i++ {
 		c := Candidate{
 			Status:      Unbonded,
 			PubKey:      pks[i],
 			Address:     addrs[i],
 			Assets:      sdk.NewRat(amts[i]),
 			Liabilities: sdk.NewRat(amts[i]),
-			VotingPower: sdk.NewRat(amts[i]),
 		}
 		keeper.setCandidate(ctx, c)
 		candidate[i] = c
diff --git a/x/stake/msg.go b/x/stake/msg.go
index 3b94b6bcb..7a75e1b8f 100644
--- a/x/stake/msg.go
+++ b/x/stake/msg.go
@@ -57,7 +57,7 @@ func (msg MsgDeclareCandidacy) ValidateBasic() sdk.Error {
 		return ErrCandidateEmpty()
 	}
 	if msg.Bond.Amount <= 0 {
-		return sdk.ErrInvalidCoins(sdk.Coins{msg.Bond})
+		return sdk.ErrInvalidCoins(sdk.Coins{msg.Bond}.String())
 	}
 	empty := Description{}
 	if msg.Description == empty {
@@ -153,7 +153,7 @@ func (msg MsgDelegate) ValidateBasic() sdk.Error {
 		return ErrBadCandidateAddr()
 	}
 	if msg.Bond.Amount <= 0 {
-		return sdk.ErrInvalidCoins(sdk.Coins{msg.Bond})
+		return sdk.ErrInvalidCoins(sdk.Coins{msg.Bond}.String())
 	}
 	return nil
 }