diff --git a/common/cosmwasm-smart-contracts/contracts-common/src/signing/mod.rs b/common/cosmwasm-smart-contracts/contracts-common/src/signing/mod.rs
index 1abf94457d..206152957b 100644
--- a/common/cosmwasm-smart-contracts/contracts-common/src/signing/mod.rs
+++ b/common/cosmwasm-smart-contracts/contracts-common/src/signing/mod.rs
@@ -98,7 +98,7 @@ pub trait SigningPurpose {
     fn message_type() -> MessageType;
 }
 
-#[derive(Serialize)]
+#[derive(Serialize, Deserialize)]
 #[serde(transparent)]
 pub struct MessageType(String);
 
@@ -137,15 +137,20 @@ impl SigningAlgorithm {
 pub struct SignableMessage<T> {
     pub nonce: u32,
     pub algorithm: SigningAlgorithm,
+    pub message_type: MessageType,
 
     pub content: T,
 }
 
-impl<T> SignableMessage<T> {
+impl<T> SignableMessage<T>
+where
+    T: SigningPurpose,
+{
     pub fn new(nonce: u32, content: T) -> Self {
         SignableMessage {
             nonce,
             algorithm: SigningAlgorithm::Ed25519,
+            message_type: T::message_type(),
             content,
         }
     }
@@ -162,7 +167,10 @@ impl<T> SignableMessage<T> {
         to_vec(self)
     }
 
-    pub fn to_sha256_plaintext_digest(&self) -> StdResult<Vec<u8>> {
+    pub fn to_sha256_plaintext_digest(&self) -> StdResult<Vec<u8>>
+    where
+        T: Serialize,
+    {
         unimplemented!()
     }
 
@@ -209,20 +217,24 @@ impl<T> SignableMessage<T> {
 
 #[derive(Serialize)]
 pub struct ContractMessageContent<T> {
-    pub message_type: MessageType,
     pub sender: Addr,
     pub proxy: Option<Addr>,
     pub funds: Vec<Coin>,
     pub data: T,
 }
 
-impl<T> ContractMessageContent<T>
+impl<T> SigningPurpose for ContractMessageContent<T>
 where
     T: SigningPurpose,
 {
+    fn message_type() -> MessageType {
+        T::message_type()
+    }
+}
+
+impl<T> ContractMessageContent<T> {
     pub fn new(sender: Addr, proxy: Option<Addr>, funds: Vec<Coin>, data: T) -> Self {
         ContractMessageContent {
-            message_type: T::message_type(),
             sender,
             proxy,
             funds,
@@ -238,7 +250,6 @@ where
         };
 
         ContractMessageContent {
-            message_type: T::message_type(),
             sender: signer,
             proxy,
             funds: info.funds,
diff --git a/common/cosmwasm-smart-contracts/contracts-common/src/signing/verifier.rs b/common/cosmwasm-smart-contracts/contracts-common/src/signing/verifier.rs
index 3bb82ccb5c..6663703d42 100644
--- a/common/cosmwasm-smart-contracts/contracts-common/src/signing/verifier.rs
+++ b/common/cosmwasm-smart-contracts/contracts-common/src/signing/verifier.rs
@@ -1,7 +1,7 @@
 // Copyright 2023 - Nym Technologies SA <contact@nymtech.net>
 // SPDX-License-Identifier: Apache-2.0
 
-use crate::signing::{MessageSignature, SignableMessage, SigningAlgorithm};
+use crate::signing::{MessageSignature, SignableMessage, SigningAlgorithm, SigningPurpose};
 use cosmwasm_std::{Api, StdError, VerificationError};
 use serde::Serialize;
 use thiserror::Error;
@@ -9,7 +9,7 @@ use thiserror::Error;
 pub trait Verifier {
     type Error: From<StdError>;
 
-    fn verify_message<T: Serialize>(
+    fn verify_message<T: Serialize + SigningPurpose>(
         &self,
         message: SignableMessage<T>,
         signature: MessageSignature,
diff --git a/contracts/mixnet/src/support/tests/mod.rs b/contracts/mixnet/src/support/tests/mod.rs
index 26b9639a05..71a2d96437 100644
--- a/contracts/mixnet/src/support/tests/mod.rs
+++ b/contracts/mixnet/src/support/tests/mod.rs
@@ -67,7 +67,7 @@ pub mod test_helpers {
         SignableMixNodeBondingMsg,
     };
     use nym_contracts_common::signing::{
-        ContractMessageContent, MessageSignature, SignableMessage, SigningAlgorithm,
+        ContractMessageContent, MessageSignature, SignableMessage, SigningAlgorithm, SigningPurpose,
     };
     use nym_crypto::asymmetric::identity;
     use nym_crypto::asymmetric::identity::KeyPair;
@@ -860,7 +860,7 @@ pub mod test_helpers {
         }
     }
 
-    pub fn ed25519_sign_message<T: Serialize>(
+    pub fn ed25519_sign_message<T: Serialize + SigningPurpose>(
         message: SignableMessage<T>,
         private_key: &identity::PrivateKey,
     ) -> MessageSignature {