diff --git a/core/src/main/java/hudson/scm/NullSCM.java b/core/src/main/java/hudson/scm/NullSCM.java
index 9db1b8eb00db9c8d41fad647baf07048f16f2215..40e562bcd187f3d101221931ce29da62df149ac0 100644
--- a/core/src/main/java/hudson/scm/NullSCM.java
+++ b/core/src/main/java/hudson/scm/NullSCM.java
@@ -58,7 +58,7 @@ public class NullSCM extends SCM {
         return NullChangeLogParser.INSTANCE;
     }
 
-    @Extension
+    @Extension(ordinal = Integer.MAX_VALUE)
     public static class DescriptorImpl extends SCMDescriptor<NullSCM> {
         public DescriptorImpl() {
             super(null);