diff --git a/CMakeLists.txt b/CMakeLists.txt
index 872f310..def370a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-# Copyright (C) 2021 IIT Istituto Italiano di Tecnologia 
+# Copyright (C) 2021 IIT Istituto Italiano di Tecnologia
 # Author: Marco Randazzo marco.randazzo@iit.it
 # CopyPolicy: Released under the terms of the GNU GPL v2.0.
 
@@ -75,7 +75,7 @@ message(STATUS "YARP is version: ${YARP_VERSION}")
 
 yarp_configure_external_installation(${PROJECT_NAME} WITH_PLUGINS)
 
-#### Find iCub 
+#### Find iCub
 find_package(ICUB)
 
 list(APPEND CMAKE_MODULE_PATH ${ICUB_MODULE_PATH})
diff --git a/src/freeFloorViewer/freeFloorThread.h b/src/freeFloorViewer/freeFloorThread.h
index 7eeddf3..04dec28 100644
--- a/src/freeFloorViewer/freeFloorThread.h
+++ b/src/freeFloorViewer/freeFloorThread.h
@@ -40,6 +40,7 @@
 #include <math.h>
 #include <mutex>
 #include <algorithm>
+#include <opencv2/opencv.hpp>
 
 #include "navigation_defines.h"