diff --git a/CHANGELOG.md b/CHANGELOG.md
index 08e88ec8e..e6f1e3fa6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,7 @@ FlatLaf Change Log
   feedback only for left mouse button.
 - ScaledImageIcon: Do not throw exceptions if image was has invalid size (e.g.
   not found). Instead, paint a red rectangle (similar to `FlatSVGIcon`).
+- Fixed NPE in `FlatUIUtils.isCellEditor()`. (issue #601)
 
 
 ## 2.5
diff --git a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatUIUtils.java b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatUIUtils.java
index f0dcd89dd..0da580534 100644
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatUIUtils.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatUIUtils.java
@@ -210,6 +210,9 @@ public static int minimumHeight( JComponent c, int minimumHeight ) {
 	}
 
 	public static boolean isCellEditor( Component c ) {
+		if( c == null )
+			return false;
+
 		// check whether used in cell editor (check 3 levels up)
 		Component c2 = c;
 		for( int i = 0; i <= 2 && c2 != null; i++ ) {