diff --git a/repo2docker/app.py b/repo2docker/app.py
index 8599b312..ee0908fe 100644
--- a/repo2docker/app.py
+++ b/repo2docker/app.py
@@ -324,6 +324,8 @@ class Repo2Docker(Application):
             elif 'error' in l:
                 self.log.info(l['error'], extra=dict(phase='failure'))
                 sys.exit(1)
+            elif 'status' in l:
+                    self.log.info('Fetching base image...\r', extra=dict(phase='building'))
             else:
                 self.log.info(json.dumps(l), extra=dict(phase='building'))
 
diff --git a/repo2docker/detectors.py b/repo2docker/detectors.py
index f6fa2d65..effbeddd 100644
--- a/repo2docker/detectors.py
+++ b/repo2docker/detectors.py
@@ -686,7 +686,7 @@ class DockerBuildPack(BuildPack):
         ):
             yield line
 
-class LegacyBinderDockerBuildPack(BuildPack):
+class LegacyBinderDockerBuildPack(DockerBuildPack):
 
     name = 'Legacy Binder Dockerfile'
 
diff --git a/tests/dockerfile/legacy/Dockerfile b/tests/dockerfile/legacy/Dockerfile
new file mode 100644
index 00000000..3320f9a3
--- /dev/null
+++ b/tests/dockerfile/legacy/Dockerfile
@@ -0,0 +1,15 @@
+FROM andrewosh/binder-base
+
+USER root
+
+# Add Julia dependencies
+RUN apt-get update
+RUN apt-get install -y julia libnettle4 && apt-get clean
+
+USER main
+
+# Install Julia kernel
+RUN julia -e 'Pkg.add("IJulia")'
+RUN julia -e 'Pkg.add("Gadfly")' && julia -e 'Pkg.add("RDatasets")'
+
+ADD verify verify
diff --git a/tests/dockerfile/legacy/verify b/tests/dockerfile/legacy/verify
new file mode 100755
index 00000000..98aebb2b
--- /dev/null
+++ b/tests/dockerfile/legacy/verify
@@ -0,0 +1,6 @@
+#!/usr/bin/env python
+import sys
+
+assert sys.version_info[:2] == (2, 7)
+
+import jupyter