diff --git a/biobox_cli/biobox_type/short_read_assembler.py b/biobox_cli/biobox_type/short_read_assembler.py
index 0bac5f9..0b88ee3 100644
--- a/biobox_cli/biobox_type/short_read_assembler.py
+++ b/biobox_cli/biobox_type/short_read_assembler.py
@@ -31,8 +31,7 @@ def run(argv):
     contig_file = opts['--output']
     task        = opts['--task']
 
-    if not ctn.image_available(image):
-        util.err_exit('unknown_image', {'image': image})
+    ctn.exit_if_no_image_available(image)
 
     cntr_fastq_file = "/fastq/input.fq.gz"
     fastq_values = [(cntr_fastq_file, "paired")]
diff --git a/biobox_cli/command/verify.py b/biobox_cli/command/verify.py
index 88e39b2..a67a418 100644
--- a/biobox_cli/command/verify.py
+++ b/biobox_cli/command/verify.py
@@ -23,8 +23,7 @@ def run(argv):
     image  = opts['<image>']
     task   = opts['--task']
 
-    if not ctn.image_available(image):
-        util.err_exit('unknown_image', {'image': image})
+    ctn.exit_if_no_image_available(image)
 
     results = behave.run(biobox, image, task)
 
diff --git a/biobox_cli/container.py b/biobox_cli/container.py
index 40b82ff..95a9422 100644
--- a/biobox_cli/container.py
+++ b/biobox_cli/container.py
@@ -1,10 +1,11 @@
-import logging
-import os
+import logging, os
 logging.getLogger("requests").setLevel(logging.WARNING)
 
 import docker
 import docker.utils
 
+import biobox_cli.util as util
+
 def client():
     client = docker.Client(**docker.utils.kwargs_from_env(assert_hostname = False))
     return client
@@ -13,19 +14,22 @@ def get_image_tags(docker_dict):
     return reduce(lambda acc, x: acc + [x, x.split(":")[0]],
             docker_dict['RepoTags'], [])
 
-def image_available_locally(image):
+def is_image_available_locally(image):
     image_tags = map(get_image_tags, client().images())
     images = set(reduce(lambda acc, x: acc + x, image_tags, []))
     return image in images
 
-def image_available(image):
-    from docker.errors import APIError
-    if not image_available_locally(image):
+def is_image_available(image):
+    if not is_image_available_locally(image):
         output = client().pull(image)
         if "error" in output:
             return False
     return True
 
+def exit_if_no_image_available(image):
+    if not is_image_available(image):
+        util.err_exit('unknown_image', {'image': image})
+
 def mount_string(host_dir, container_dir, read_only = True):
     access = "ro" if read_only else "rw"
     return ":".join([os.path.abspath(host_dir), container_dir, access])
diff --git a/test/test_container.py b/test/test_container.py
index e254815..28e54a0 100644
--- a/test/test_container.py
+++ b/test/test_container.py
@@ -7,19 +7,19 @@ def test_get_client():
     ctn.client()
 
 def test_checking_a_local_available_image():
-    nose.assert_equal(ctn.image_available_locally("python"), True)
+    nose.assert_equal(ctn.is_image_available_locally("python"), True)
 
 def test_checking_an_local_available_image_with_tag():
-    nose.assert_equal(ctn.image_available_locally("python:2.7"), True)
+    nose.assert_equal(ctn.is_image_available_locally("python:2.7"), True)
 
 def test_checking_a_locally_non_existent_image():
-    nose.assert_equal(ctn.image_available_locally("biobox/unknown"), False)
+    nose.assert_equal(ctn.is_image_available_locally("biobox/unknown"), False)
 
 def test_checking_an_available_image():
-    nose.assert_equal(ctn.image_available("python"), True)
+    nose.assert_equal(ctn.is_image_available("python"), True)
 
 def test_checking_an_available_image_with_tag():
-    nose.assert_equal(ctn.image_available("python:2.7"), True)
+    nose.assert_equal(ctn.is_image_available("python:2.7"), True)
 
 def test_create_mount_string_with_relative_dir():
     expected = "{}/tmp:/tmp:ro".format(hlpr.project_root())