diff --git a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatButtonUI.java b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatButtonUI.java
index 30530a7f..922c6663 100644
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatButtonUI.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatButtonUI.java
@@ -149,6 +149,10 @@ public class FlatButtonUI
 				shadowWidth = FlatUIUtils.getUIInt( "Button.shadowWidth", 2 );
 				shadowColor = UIManager.getColor( "Button.shadowColor" );
 				defaultShadowColor = UIManager.getColor( "Button.default.shadowColor" );
+			} else {
+				shadowWidth = 0;
+				shadowColor = null;
+				defaultShadowColor = null;
 			}
 
 			defaultBackground = FlatUIUtils.getUIColor( "Button.default.startBackground", "Button.default.background" );