diff --git a/x/slashing/msg.go b/x/slashing/msg.go
index 72d2255d6..d2676af81 100644
--- a/x/slashing/msg.go
+++ b/x/slashing/msg.go
@@ -1,11 +1,12 @@
 package slashing
 
 import (
-	"encoding/json"
-
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/wire"
 )
 
+var cdc = wire.NewCodec()
+
 // name to identify transaction types
 const MsgType = "slashing"
 
@@ -29,7 +30,7 @@ func (msg MsgUnrevoke) GetSigners() []sdk.Address { return []sdk.Address{msg.Val
 
 // get the bytes for the message signer to sign on
 func (msg MsgUnrevoke) GetSignBytes() []byte {
-	b, err := json.Marshal(msg)
+	b, err := cdc.MarshalJSON(msg)
 	if err != nil {
 		panic(err)
 	}