diff --git a/protocol/localtxsubmission/localtxsubmission.go b/protocol/localtxsubmission/localtxsubmission.go
index 91ef8c4e..091e834f 100644
--- a/protocol/localtxsubmission/localtxsubmission.go
+++ b/protocol/localtxsubmission/localtxsubmission.go
@@ -83,7 +83,7 @@ type CallbackContext struct {
 }
 
 // Callback function types
-type SubmitTxFunc func(CallbackContext, interface{}) error
+type SubmitTxFunc func(CallbackContext, MsgSubmitTxTransaction) error
 
 // New returns a new LocalTxSubmission object
 func New(