diff --git a/plugins/maissensor/include/yarp/dev/MaisSensorDriver.h b/plugins/maissensor/include/yarp/dev/MaisSensorDriver.h
index e71414855..61b842230 100644
--- a/plugins/maissensor/include/yarp/dev/MaisSensorDriver.h
+++ b/plugins/maissensor/include/yarp/dev/MaisSensorDriver.h
@@ -122,7 +122,7 @@ class yarp::dev::GazeboYarpMaisSensorDriver:
 
     yarp::os::Stamp m_lastTimestamp; /**< timestamp, updated with simulation time at each onUpdate call */
 
-    std::mutex m_mutex;
+    mutable std::mutex m_mutex;
     yarp::sig::VectorOf<JointType> m_jointTypes;
 
     int m_channels_num;