diff --git a/core/src/main/java/hudson/Functions.java b/core/src/main/java/hudson/Functions.java
index f6f9979afd8a6d9b7ea735e96bb444364a4b5483..b7a561aea221193c714601140e97b8dd6957c467 100644
--- a/core/src/main/java/hudson/Functions.java
+++ b/core/src/main/java/hudson/Functions.java
@@ -191,7 +191,7 @@ public class Functions {
     
     @Deprecated
     public static boolean isMatrixProject(Object o) {
-        return o.getClass().getName().equals("hudson.matrix.MatrixProject");
+        return o != null && o.getClass().getName().equals("hudson.matrix.MatrixProject");
     }
 
     public static String xsDate(Calendar cal) {