diff --git a/lib/CalypOpenCVModuleIf.cpp b/lib/CalypOpenCVModuleIf.cpp
index d52fa45..fdd6055 100644
--- a/lib/CalypOpenCVModuleIf.cpp
+++ b/lib/CalypOpenCVModuleIf.cpp
@@ -25,7 +25,6 @@
 #include "CalypOpenCVModuleIf.h"
 
 // OpenCV
-#include <opencv2/core/mat.hpp>
 #include <opencv2/opencv.hpp>
 
 using cv::Mat;
diff --git a/lib/CalypOpenCVModuleIf.h b/lib/CalypOpenCVModuleIf.h
index 142d5cc..ea4ef34 100644
--- a/lib/CalypOpenCVModuleIf.h
+++ b/lib/CalypOpenCVModuleIf.h
@@ -28,6 +28,11 @@
 
 #include "CalypModuleIf.h"
 
+namespace cv
+{
+class Mat;
+}
+
 /**
  * \class    CalypOpenCVModuleIf
  * \ingroup  CalypLib Calyp_Modules