diff --git a/core/src/main/java/hudson/Functions.java b/core/src/main/java/hudson/Functions.java
index 2dc9f163c7..04ba6a3075 100644
--- a/core/src/main/java/hudson/Functions.java
+++ b/core/src/main/java/hudson/Functions.java
@@ -190,7 +190,7 @@ 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) {