diff --git a/girder_worker/plugins/docker/__init__.py b/girder_worker/plugins/docker/__init__.py
index bc6f62b8..85ad2a9d 100644
--- a/girder_worker/plugins/docker/__init__.py
+++ b/girder_worker/plugins/docker/__init__.py
@@ -2,8 +2,12 @@
 import shutil
 import subprocess
 import tempfile
+import time
 from girder_worker import config
 
+# Minimum interval in seconds at which to run the docker-gc script
+MIN_GC_INTERVAL = 600
+
 
 def before_run(e):
     import executor
@@ -28,6 +32,13 @@ def docker_gc(e):
     the same directory as this file. After that, deletes all images that are
     no longer used by any containers.
     """
+    stampfile = os.path.join(config.get('girder_worker', 'tmp_root'), '.dockergcstamp')
+    if os.path.exists(stampfile) and time.time() - os.path.getmtime(stampfile) < MIN_GC_INTERVAL:
+        return
+    else:  # touch the file
+        with open(stampfile, 'w') as f:
+            f.write('')
+
     print('Garbage collecting docker containers and images.')
     gc_dir = tempfile.mkdtemp()
 
diff --git a/girder_worker/plugins/docker/tests/docker_test.py b/girder_worker/plugins/docker/tests/docker_test.py
index 80f26a80..8c44f6e2 100644
--- a/girder_worker/plugins/docker/tests/docker_test.py
+++ b/girder_worker/plugins/docker/tests/docker_test.py
@@ -194,6 +194,7 @@ def fetchMock(url, request):
 
     @mock.patch('subprocess.Popen')
     def testCleanupHook(self, mockPopen):
+        os.mkdir(_tmp)
         mockPopen.return_value = processMock
         girder_worker.config.set('docker', 'cache_timeout', '123456')
         girder_worker.config.set('docker', 'exclude_images', 'test/test:latest')
diff --git a/girder_worker/tasks.py b/girder_worker/tasks.py
index 0bd95934..d87439b6 100644
--- a/girder_worker/tasks.py
+++ b/girder_worker/tasks.py
@@ -3,7 +3,11 @@
 from .app import app
 
 
-@app.task(name='girder_worker.run')
+def _cleanup():
+    core.events.trigger('cleanup')
+
+
+@app.task(name='girder_worker.run', after_return=_cleanup)
 def run(*pargs, **kwargs):
     jobInfo = kwargs.pop('jobInfo', {})
     retval = 0