diff --git a/core/transcoder.py b/core/transcoder.py
index 6dc9ce32..d4b7e2f2 100644
--- a/core/transcoder.py
+++ b/core/transcoder.py
@@ -713,7 +713,7 @@ def combine_vts(vts_path):
 
 def combine_cd(combine):
     new_files = []
-    for item in set([re.match('(.+)[cC][dD][0-9].', item).groups()[0] for item in combine]):
+    for item in {re.match('(.+)[cC][dD][0-9].', item).groups()[0] for item in combine}:
         concat = ''
         for n in range(99):
             files = [file for file in combine if
diff --git a/core/utils/paths.py b/core/utils/paths.py
index dba119f5..fe049ae7 100644
--- a/core/utils/paths.py
+++ b/core/utils/paths.py
@@ -67,10 +67,10 @@ def remote_dir(path):
 
 def get_dir_size(input_path):
     prepend = partial(os.path.join, input_path)
-    return sum([
+    return sum(
         (os.path.getsize(f) if os.path.isfile(f) else get_dir_size(f))
         for f in map(prepend, os.listdir(text_type(input_path)))
-    ])
+    )
 
 
 def remove_empty_folders(path, remove_root=True):
diff --git a/tox.ini b/tox.ini
index 77e5ae63..56d21272 100644
--- a/tox.ini
+++ b/tox.ini
@@ -50,6 +50,7 @@ per-file-ignores =
 deps =
     flake8
     flake8-commas
+    flake8-comprehensions
     flake8-quotes
 skip_install = true
 commands =