diff --git a/src/QtOpenCV.cpp b/src/QtOpenCV.cpp
index f7bfd447..b60cdb21 100644
--- a/src/QtOpenCV.cpp
+++ b/src/QtOpenCV.cpp
@@ -39,7 +39,7 @@ cv::Mat cvtQImage2CvMat(const QImage & image)
 		cvImage = cv::Mat(image.height(), image.width(), CV_8UC3);
 		unsigned char * data = cvImage.data;
 		const IplImage test = cvImage;
-		printf("%d vs %d\n", cvImage.cols*cvImage.elemSize(), test.widthStep);
+		printf("%d vs %d\n", cvImage.cols*int(cvImage.elemSize()), test.widthStep);
 		for(int y = 0; y < image.height(); ++y, data+=cvImage.cols*cvImage.elemSize())
 		{
 			for(int x = 0; x < image.width(); ++x)