src/java.desktop/unix/classes/sun/awt/X11/XToolkit.java

@@ -1568,10 +1568,14 @@
         if (!GraphicsEnvironment.isHeadless()) {
             desktopProperties.put("awt.multiClickInterval",
                                   Integer.valueOf(getMultiClickTime()));
             desktopProperties.put("awt.mouse.numButtons",
                                   Integer.valueOf(getNumberOfButtons()));
+            if(SunGraphicsEnvironment.isUIScaleEnabled()) {
+                addPropertyChangeListener("gnome.Xft/DPI", evt ->
+                                                     localEnv.displayChanged());
+            }
         }
     }
 
     /**
      * This method runs through the XPointer and XExtendedPointer array.