diff --git a/src/monitor.h b/src/monitor.h
index 870657d..913f966 100644
--- a/src/monitor.h
+++ b/src/monitor.h
@@ -136,7 +136,10 @@ class BridgeMonitor: public Stream {
 
         k_mutex_lock(&monitor_mutex, K_FOREVER);
 
-        if (!_connected) return;
+        if (!_connected) {
+            k_mutex_unlock(&monitor_mutex);
+            return;
+        }
 
         MsgPack::arr_t<uint8_t> message;
         RpcResult async_rpc = bridge->call(MON_READ_METHOD, size);
diff --git a/src/tcp_client.h b/src/tcp_client.h
index a8fef79..9a1ca90 100644
--- a/src/tcp_client.h
+++ b/src/tcp_client.h
@@ -187,7 +187,10 @@ class BridgeTCPClient : public Client {
 
         k_mutex_lock(&client_mutex, K_FOREVER);
 
-        if (!_connected) return;
+        if (!_connected) {
+            k_mutex_unlock(&client_mutex);
+            return;
+        }
 
         MsgPack::arr_t<uint8_t> message;
         RpcResult async_rpc = bridge->call(TCP_READ_METHOD, connection_id, size);