diff --git a/workers/dockerfilebuild.py b/workers/dockerfilebuild.py
index 477e0282a..027240287 100644
--- a/workers/dockerfilebuild.py
+++ b/workers/dockerfilebuild.py
@@ -206,6 +206,10 @@ class DockerfileBuildContext(object):
 
     # Pull the image, in case it was updated since the last build
     image_and_tag = ':'.join(self._parsed_dockerfile.get_image_and_tag())
+    if image_and_tag is None or image_and_tag[0] is None:
+      self._build_logger('Missing FROM command in Dockerfile', build_logs.ERROR)
+      raise JobException('Missing FROM command in Dockerfile')
+
     self._build_logger('Pulling base image: %s' % image_and_tag)
     pull_status = self._build_cl.pull(image_and_tag, stream=True)