diff --git a/zuul/manager/__init__.py b/zuul/manager/__init__.py
index 58ad607..32f0cbb 100644
--- a/zuul/manager/__init__.py
+++ b/zuul/manager/__init__.py
@@ -13,7 +13,6 @@
 import logging
 
 from zuul import exceptions
-from zuul.model import NullChange
 
 
 class DynamicChangeQueueContextManager(object):
@@ -682,9 +681,8 @@
             build_set.commit = event.commit
             build_set.files.setFiles(event.files)
         elif event.updated:
-            if not isinstance(item.change, NullChange):
-                build_set.commit = item.change.newrev
-        if not build_set.commit and not isinstance(item.change, NullChange):
+            build_set.commit = item.change.newrev
+        if not build_set.commit:
             self.log.info("Unable to merge change %s" % item.change)
             item.setUnableToMerge()
 
diff --git a/zuul/model.py b/zuul/model.py
index 4663a5a..5ed2fbd 100644
--- a/zuul/model.py
+++ b/zuul/model.py
@@ -1695,25 +1695,6 @@
         return False
 
 
-class NullChange(Ref):
-    # TODOv3(jeblair): remove this in favor of enqueueing Refs (eg
-    # current master) instead.
-    def __repr__(self):
-        return '<NullChange for %s>' % (self.project)
-
-    def _id(self):
-        return None
-
-    def equals(self, other):
-        if (self.project == other.project
-            and other._id() is None):
-            return True
-        return False
-
-    def isUpdateOf(self, other):
-        return False
-
-
 class TriggerEvent(object):
     """Incoming event from an external system."""
     def __init__(self):