diff --git a/modules/highgui/src/window_gtk.cpp b/modules/highgui/src/window_gtk.cpp
index b5b6c0dc7c..152bc07e46 100644
--- a/modules/highgui/src/window_gtk.cpp
+++ b/modules/highgui/src/window_gtk.cpp
@@ -465,6 +465,7 @@ CV_IMPL int cvInitSystem( int argc, char** argv )
         hg_windows = 0;
 
         gtk_init( &argc, &argv );
+        setlocale(LC_NUMERIC, "en_US.utf8");
 
         #ifdef HAVE_OPENGL
             gtk_gl_init(&argc, &argv);