diff --git a/src/Simplex/Messaging/Agent.hs b/src/Simplex/Messaging/Agent.hs
index 5d72cc511..cb6836b47 100644
--- a/src/Simplex/Messaging/Agent.hs
+++ b/src/Simplex/Messaging/Agent.hs
@@ -478,7 +478,7 @@ newConnNoQueues c userId connId enableNtfs cMode = do
 
 joinConnAsync :: AgentMonad m => AgentClient -> UserId -> ACorrId -> Bool -> ConnectionRequestUri c -> ConnInfo -> SubscriptionMode -> m ConnId
 joinConnAsync c userId corrId enableNtfs cReqUri@(CRInvitationUri ConnReqUriData {crAgentVRange} _) cInfo subMode = do
-  withInvLock c (B.unpack . strEncode $ cReqUri) "joinConnAsync" $ do
+  withInvLock c (strEncode cReqUri) "joinConnAsync" $ do
     aVRange <- asks $ smpAgentVRange . config
     case crAgentVRange `compatibleVersion` aVRange of
       Just (Compatible connAgentVersion) -> do
@@ -614,7 +614,7 @@ startJoinInvitation userId connId enableNtfs (CRInvitationUri ConnReqUriData {cr
 
 joinConnSrv :: AgentMonad m => AgentClient -> UserId -> ConnId -> Bool -> ConnectionRequestUri c -> ConnInfo -> SubscriptionMode -> SMPServerWithAuth -> m ConnId
 joinConnSrv c userId connId enableNtfs inv@CRInvitationUri {} cInfo subMode srv =
-  withInvLock c (B.unpack . strEncode $ inv) "joinConnSrv" $ do
+  withInvLock c (strEncode inv) "joinConnSrv" $ do
     (aVersion, cData@ConnData {connAgentVersion}, q, rc, e2eSndParams) <- startJoinInvitation userId connId enableNtfs inv
     g <- asks idsDrg
     connId' <- withStore c $ \db -> runExceptT $ do
diff --git a/src/Simplex/Messaging/Agent/Client.hs b/src/Simplex/Messaging/Agent/Client.hs
index 817978647..e9bc8b520 100644
--- a/src/Simplex/Messaging/Agent/Client.hs
+++ b/src/Simplex/Messaging/Agent/Client.hs
@@ -249,7 +249,7 @@ data AgentClient = AgentClient
     -- locks to prevent concurrent operations with connection
     connLocks :: TMap ConnId Lock,
     -- locks to prevent concurrent operations with connection request invitations
-    invLocks :: TMap String Lock,
+    invLocks :: TMap ByteString Lock,
     -- lock to prevent concurrency between periodic and async connection deletions
     deleteLock :: Lock,
     -- locks to prevent concurrent reconnections to SMP servers
@@ -653,7 +653,7 @@ withConnLock :: MonadUnliftIO m => AgentClient -> ConnId -> String -> m a -> m a
 withConnLock _ "" _ = id
 withConnLock AgentClient {connLocks} connId name = withLockMap_ connLocks connId name
 
-withInvLock :: MonadUnliftIO m => AgentClient -> String -> String -> m a -> m a
+withInvLock :: MonadUnliftIO m => AgentClient -> ByteString -> String -> m a -> m a
 withInvLock AgentClient {invLocks} = withLockMap_ invLocks
 
 withLockMap_ :: (Ord k, MonadUnliftIO m) => TMap k Lock -> k -> String -> m a -> m a