diff --git a/master/buildbot/schedulers/basic.py b/master/buildbot/schedulers/basic.py
index 56e02e7cd28..c889dd34d06 100644
--- a/master/buildbot/schedulers/basic.py
+++ b/master/buildbot/schedulers/basic.py
@@ -97,17 +97,15 @@ def activate(self):
         # if we have a treeStableTimer, if there are classified changes
         # out there, start their timers again
         if self.treeStableTimer:
-            d = self.scanExistingClassifiedChanges()
+            yield self.scanExistingClassifiedChanges()
 
         # otherwise, we don't care about classified
         # changes, so get rid of any hanging around from previous
         # configurations
         else:
-            d = self.master.db.schedulers.flushChangeClassifications(
+            yield self.master.db.schedulers.flushChangeClassifications(
                 self.objectid)
 
-        yield d
-
     @defer.inlineCallbacks
     def deactivate(self):
         # the base deactivate will unsubscribe from new changes
diff --git a/master/buildbot/schedulers/timed.py b/master/buildbot/schedulers/timed.py
index bce044da4e1..f94c74ba821 100644
--- a/master/buildbot/schedulers/timed.py
+++ b/master/buildbot/schedulers/timed.py
@@ -44,7 +44,7 @@ def convertBranchParameter(kwargs):
         }}
 
 
-class Timed(base.BaseScheduler):
+class Timed(base.BaseScheduler, AbsoluteSourceStampsMixin):
 
     """
     Parent class for timed schedulers.  This takes care of the (surprisingly
@@ -149,7 +149,7 @@ def gotChange(self, change, important):
         return d
 
     @defer.inlineCallbacks
-    def startBuild(self, **kwargs):
+    def startBuild(self):
         # use the collected changes to start a build
         scheds = self.master.db.schedulers
         classifications = yield scheds.getChangeClassifications(self.objectid)
@@ -167,8 +167,7 @@ def startBuild(self, **kwargs):
         if changeids:
             max_changeid = changeids[-1]  # (changeids are sorted)
             yield self.addBuildsetForChanges(reason=self.reason,
-                                             changeids=changeids,
-                                             **kwargs)
+                                             changeids=changeids)
             yield scheds.flushChangeClassifications(self.objectid,
                                                     less_than=max_changeid + 1)
         else:
@@ -177,8 +176,7 @@ def startBuild(self, **kwargs):
             sourcestamps = [dict(codebase=cb) for cb in self.codebases.keys()]
             yield self.addBuildsetForSourceStampsWithDefaults(
                 reason=self.reason,
-                sourcestamps=sourcestamps,
-                **kwargs)
+                sourcestamps=sourcestamps)
 
     def getCodebaseDict(self, codebase):
         if self.createAbsoluteSourceStamps:
@@ -331,7 +329,7 @@ def getNextBuildTime(self, lastActuated):
         return defer.succeed(nextdate)
 
 
-class Nightly(NightlyBase, AbsoluteSourceStampsMixin):
+class Nightly(NightlyBase):
     compare_attrs = ('fileIsImportant', 'change_filter', 'onlyImportant',)
 
     def __init__(self, name, builderNames, minute=0, hour='*',