diff --git a/CHANGELOG.md b/CHANGELOG.md
index 838c8825..08e88ec8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,9 @@ FlatLaf Change Log
 
 - ComboBox and Spinner: Fixed missing arrow buttons if preferred height is zero.
   Minimum width of arrow buttons is 3/4 of default width.
+- MenuBar: Fixed NPE in `FlatMenuItemRenderer.getTopLevelFont()` if menu item
+  does not have a parent. (issue #600; regression since implementing #589 in
+  FlatLaf 2.5)
 - TabbedPane: Switch and close tabs on left mouse click only. (PR #595)
 - ScrollBar: Show "pressed" feedback on track/thumb only for left mouse button.
   If absolute positioning is enabled (the default), then also for middle mouse
diff --git a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuItemRenderer.java b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuItemRenderer.java
index 1f556a85..0e454b70 100644
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuItemRenderer.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuItemRenderer.java
@@ -500,7 +500,11 @@ debug*/
 
 	private Font getTopLevelFont() {
 		Font font = menuItem.getFont();
-		return (font != menuFont) ? font : menuItem.getParent().getFont();
+		// menu item parent may be null if JMenu.isTopLevelMenu() is overridden
+		// and does not check parent (e.g. com.jidesoft.swing.JideMenu.isTopLevelMenu())
+		return (font != menuFont || menuItem.getParent() == null)
+			? font
+			: menuItem.getParent().getFont();
 	}
 
 	private Icon getIconForPainting() {