diff --git a/tests/unit/test_circular_dependencies.py b/tests/unit/test_circular_dependencies.py
index 9c67e45ba5..802ff570a5 100644
--- a/tests/unit/test_circular_dependencies.py
+++ b/tests/unit/test_circular_dependencies.py
@@ -3576,11 +3576,11 @@ class TestGerritCircularDependencies(ZuulTestCase):
         self.assertEqual(0, counters[('changes', '1', 'submitted_together')])
         self.assertEqual(0, counters[('changes', '2', 'submitted_together')])
         self.assertEqual(0, counters[('changes', '3', 'submitted_together')])
-        # This query happens once for each event.
+        # This query happens once for each event (but is cached).
         # * A+B+C: 3x scheduler, 0x pipeline
         qstring = ('?n=500&o=CURRENT_REVISION&o=CURRENT_COMMIT&'
                    'q=status%3Aopen%20topic%3A%22test-topic%22')
-        self.assertEqual(3, counters[('changes', qstring)])
+        self.assertEqual(1, counters[('changes', qstring)])
         self.assertHistory([
             dict(name="project-job", changes="3,1 2,1 1,1"),
             dict(name="project1-job", changes="3,1 2,1 1,1"),
diff --git a/tests/unit/test_scheduler.py b/tests/unit/test_scheduler.py
index f9034a1a15..95563b0cdf 100644
--- a/tests/unit/test_scheduler.py
+++ b/tests/unit/test_scheduler.py
@@ -9429,7 +9429,7 @@ class TestEventProcessing(ZuulTestCase):
         orig = zuul.scheduler.Scheduler._forward_trigger_event
 
         def patched_forward(obj, *args, **kw):
-            if args[1].name == 'tenant-one':
+            if args[2].name == 'tenant-one':
                 raise Exception("test")
             return orig(obj, *args, **kw)
 
diff --git a/zuul/scheduler.py b/zuul/scheduler.py
index 953fe7f33e..bbb30ce4c6 100644
--- a/zuul/scheduler.py
+++ b/zuul/scheduler.py
@@ -2429,6 +2429,7 @@ class Scheduler(threading.Thread):
         self.log.debug("Finished connection cache maintenance")
 
     def process_tenant_trigger_queue(self, tenant):
+        query_cache = QueryCache()
         try:
             with trigger_queue_lock(
                 self.zk_client, tenant.name, blocking=False
@@ -2466,7 +2467,8 @@ class Scheduler(threading.Thread):
                                 links=[
                                     trace.Link(trigger_span.get_span_context())
                                 ]):
-                            self._forward_trigger_event(event, tenant)
+                            self._forward_trigger_event(query_cache,
+                                                        event, tenant)
                     except Exception:
                         log.exception("Unable to forward event %s "
                                       "to tenant %s", event, tenant.name)
@@ -2477,7 +2479,7 @@ class Scheduler(threading.Thread):
             self.log.debug("Skipping locked trigger event queue in tenant %s",
                            tenant.name)
 
-    def _forward_trigger_event(self, event, tenant):
+    def _forward_trigger_event(self, query_cache, event, tenant):
         log = get_annotated_logger(self.log, event.zuul_event_id)
         trusted, project = tenant.getProject(event.canonical_project_name)
 
@@ -2565,7 +2567,6 @@ class Scheduler(threading.Thread):
         span.set_attribute("reconfigure_tenant", reconfigure_tenant)
         event.span_context = tracing.getSpanContext(span)
 
-        query_cache = QueryCache()
         for pipeline in tenant.layout.pipelines.values():
             # For most kinds of dependencies, it's sufficient to check
             # if this change is already in the pipeline, because the