diff --git a/node/actors/bft/src/leader/replica_commit.rs b/node/actors/bft/src/leader/replica_commit.rs
index 2f038969..ff35c65d 100644
--- a/node/actors/bft/src/leader/replica_commit.rs
+++ b/node/actors/bft/src/leader/replica_commit.rs
@@ -50,6 +50,9 @@ pub(crate) enum Error {
     /// Invalid message signature.
     #[error("invalid signature: {0:#}")]
     InvalidSignature(#[source] validator::Error),
+    /// Unexpected error when creating justification from received messages.
+    #[error("create justification unexpected error: {0:#}")]
+    CreateJustificationUnexpectedError(#[source] anyhow::Error),
 }
 
 impl StateMachine {
@@ -157,9 +160,14 @@ impl StateMachine {
             .cloned()
             .collect::<Vec<_>>();
 
+        // Clean the caches.
+        self.block_proposal_cache = None;
+        self.prepare_message_cache.retain(|k, _| k >= &self.view);
+        self.commit_message_cache.retain(|k, _| k >= &self.view);
+
         // Create the justification for our message.
         let justification = validator::CommitQC::from(&replica_messages, &consensus.validator_set)
-            .expect("Couldn't create justification from valid replica messages!");
+            .map_err(Error::CreateJustificationUnexpectedError)?;
 
         // Broadcast the leader commit message to all replicas (ourselves included).
         let output_message = ConsensusInputMessage {
@@ -175,11 +183,6 @@ impl StateMachine {
         };
         consensus.pipe.send(output_message.into());
 
-        // Clean the caches.
-        self.block_proposal_cache = None;
-        self.prepare_message_cache.retain(|k, _| k >= &self.view);
-        self.commit_message_cache.retain(|k, _| k >= &self.view);
-
         Ok(())
     }
 }
diff --git a/node/actors/bft/src/leader/replica_prepare.rs b/node/actors/bft/src/leader/replica_prepare.rs
index 3576892e..c1f958a1 100644
--- a/node/actors/bft/src/leader/replica_prepare.rs
+++ b/node/actors/bft/src/leader/replica_prepare.rs
@@ -62,6 +62,9 @@ pub(crate) enum Error {
     /// Invalid `HighQC` message.
     #[error("invalid high QC: {0:#}")]
     InvalidHighQC(#[source] anyhow::Error),
+    /// Unexpected error when creating justification from received messages.
+    #[error("create justification unexpected error: {0:#}")]
+    CreateJustificationUnexpectedError(#[source] anyhow::Error),
 }
 
 impl StateMachine {
@@ -225,7 +228,7 @@ impl StateMachine {
 
         // Create the justification for our message.
         let justification = validator::PrepareQC::from(&replica_messages, &consensus.validator_set)
-            .expect("Couldn't create justification from valid replica messages!");
+            .map_err(Error::CreateJustificationUnexpectedError)?;
 
         // Broadcast the leader prepare message to all replicas (ourselves included).
         let output_message = ConsensusInputMessage {