diff --git a/src/upnp/protocol/igd.h b/src/upnp/protocol/igd.h
index 8e8e5a9..19f773a 100644
--- a/src/upnp/protocol/igd.h
+++ b/src/upnp/protocol/igd.h
@@ -50,32 +50,32 @@
 
     IpAddr getLocalIp() const
     {
-        std::lock_guard<std::mutex> lock(mutex_);
+        std::lock_guard lock(mutex_);
         return localIp_;
     }
     IpAddr getPublicIp() const
     {
-        std::lock_guard<std::mutex> lock(mutex_);
+        std::lock_guard lock(mutex_);
         return publicIp_;
     }
     void setLocalIp(const IpAddr& addr)
     {
-        std::lock_guard<std::mutex> lock(mutex_);
+        std::lock_guard lock(mutex_);
         localIp_ = addr;
     }
     void setPublicIp(const IpAddr& addr)
     {
-        std::lock_guard<std::mutex> lock(mutex_);
+        std::lock_guard lock(mutex_);
         publicIp_ = addr;
     }
     void setUID(const std::string& uid)
     {
-        std::lock_guard<std::mutex> lock(mutex_);
+        std::lock_guard lock(mutex_);
         uid_ = uid;
     }
     std::string getUID() const
     {
-        std::lock_guard<std::mutex> lock(mutex_);
+        std::lock_guard lock(mutex_);
         return uid_;
     }