diff --git a/platform/platform-impl/src/com/intellij/ide/ui/laf/darcula/ui/DarculaButtonUI.java b/platform/platform-impl/src/com/intellij/ide/ui/laf/darcula/ui/DarculaButtonUI.java
index 570c63ed3e6d..0ff5841c843f 100644
--- a/platform/platform-impl/src/com/intellij/ide/ui/laf/darcula/ui/DarculaButtonUI.java
+++ b/platform/platform-impl/src/com/intellij/ide/ui/laf/darcula/ui/DarculaButtonUI.java
@@ -46,7 +46,7 @@ public class DarculaButtonUI extends BasicButtonUI {
   }
 
   public static boolean isSquare(Component c) {
-    return c instanceof JButton && "square".equals(((JButton)c).getClientProperty("JButton.buttonType"));
+    return c instanceof AbstractButton && "square".equals(((AbstractButton)c).getClientProperty("JButton.buttonType"));
   }
 
   public static boolean isDefaultButton(JComponent c) {