diff --git a/modules/highgui/src/window.cpp b/modules/highgui/src/window.cpp
index 6801bd8a4b..1e47bf6ee3 100644
--- a/modules/highgui/src/window.cpp
+++ b/modules/highgui/src/window.cpp
@@ -259,11 +259,11 @@ void cv::imshow( const string& winname, InputArray _img )
     const Size size = _img.size();
 #ifndef HAVE_OPENGL
     CV_Assert(size.width>0 && size.height>0);
-	{
+    {
         Mat img = _img.getMat();
         CvMat c_img = img;
         cvShowImage(winname.c_str(), &c_img);
-	}
+    }
 #else
     const double useGl = getWindowProperty(winname, WND_PROP_OPENGL);
     CV_Assert(size.width>0 && size.height>0);