diff --git a/lib/Slic3r/GUI/PreviewCanvas.pm b/lib/Slic3r/GUI/PreviewCanvas.pm
index ee2cf302e..25b5de93c 100644
--- a/lib/Slic3r/GUI/PreviewCanvas.pm
+++ b/lib/Slic3r/GUI/PreviewCanvas.pm
@@ -594,6 +594,8 @@ sub Render {
             }
         }
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+        glFlush();
+        glFinish();
         glEnable(GL_LIGHTING);
     }
     # draw objects