diff --git a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuBarBorder.java b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuBarBorder.java
index 2c361941..6ba8d159 100644
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuBarBorder.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuBarBorder.java
@@ -53,7 +53,7 @@ public class FlatMenuBarBorder
 
 	@Override
 	public void paintBorder( Component c, Graphics g, int x, int y, int width, int height ) {
-		if( !showBottomSeparator() )
+		if( !showBottomSeparator( c ) )
 			return;
 
 		float lineHeight = scale( (float) 1 );
@@ -73,7 +73,7 @@ public class FlatMenuBarBorder
 	}
 
 	/** @since 2 */
-	protected boolean showBottomSeparator() {
-		return !UIManager.getBoolean( "TitlePane.unifiedBackground" );
+	protected boolean showBottomSeparator( Component c ) {
+		return !FlatMenuBarUI.useUnifiedBackground( c );
 	}
 }
diff --git a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuBarUI.java b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuBarUI.java
index b2ffd44f..f1d9e038 100644
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuBarUI.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatMenuBarUI.java
@@ -17,6 +17,7 @@
 package com.formdev.flatlaf.ui;
 
 import java.awt.Color;
+import java.awt.Component;
 import java.awt.Graphics;
 import java.awt.Insets;
 import java.awt.Window;
@@ -189,10 +190,8 @@ public class FlatMenuBarUI
 			return background;
 
 		// use parent background for unified title pane
-		// (not storing value of "TitlePane.unifiedBackground" in class to allow changing at runtime)
-		if( UIManager.getBoolean( "TitlePane.unifiedBackground" ) &&
-			FlatNativeWindowBorder.hasCustomDecoration( (Window) rootPane.getParent() ) )
-		  background = FlatUIUtils.getParentBackground( c );
+		if( useUnifiedBackground( c ) )
+			background = FlatUIUtils.getParentBackground( c );
 
 		// paint background in full screen mode
 		if( FlatUIUtils.isFullScreen( rootPane ) )
@@ -202,6 +201,22 @@ public class FlatMenuBarUI
 		return FlatRootPaneUI.isMenuBarEmbedded( rootPane ) ? null : background;
 	}
 
+	/**@since 2 */
+	static boolean useUnifiedBackground( Component c ) {
+		// check whether:
+		// - TitlePane.unifiedBackground is true and
+		// - menu bar is the "main" menu bar and
+		// - window has custom decorations enabled
+
+		JRootPane rootPane;
+		// (not storing value of "TitlePane.unifiedBackground" in class to allow changing at runtime)
+		return UIManager.getBoolean( "TitlePane.unifiedBackground" ) &&
+			(rootPane = SwingUtilities.getRootPane( c )) != null &&
+			rootPane.getParent() instanceof Window &&
+			rootPane.getJMenuBar() == c &&
+			FlatNativeWindowBorder.hasCustomDecoration( (Window) rootPane.getParent() );
+	}
+
 	//---- class TakeFocus ----------------------------------------------------
 
 	/**
diff --git a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTitlePane.java b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTitlePane.java
index 7ff684e6..128af0b4 100644
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTitlePane.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTitlePane.java
@@ -870,7 +870,7 @@ debug*/
 			Border menuBarBorder = getMenuBarBorder();
 			if( menuBarBorder != null ) {
 				// if menu bar is embedded, paint menu bar border
-				menuBarBorder.paintBorder( c, g, x, y, width, height );
+				menuBarBorder.paintBorder( rootPane.getJMenuBar(), g, x, y, width, height );
 			} else if( borderColor != null && (rootPane.getJMenuBar() == null || !rootPane.getJMenuBar().isVisible()) ) {
 				// paint border between title pane and content if border color is specified
 				float lineHeight = UIScale.scale( (float) 1 );