diff --git a/pkgs/development/python-modules/slackclient/default.nix b/pkgs/development/python-modules/slackclient/default.nix
index 330ca7adf98a..4715e58d36be 100644
--- a/pkgs/development/python-modules/slackclient/default.nix
+++ b/pkgs/development/python-modules/slackclient/default.nix
@@ -10,10 +10,8 @@
 , mock
 , moto
 , psutil
-, pytest-cov
 , pytest-mock
 , pytestCheckHook
-, pytest-runner
 , requests
 , responses
 , sqlalchemy
@@ -55,8 +53,10 @@ buildPythonPackage rec {
     websockets
   ];
 
-  # Exclude tests that requires network features
-  pytestFlagsArray = [ "--ignore=integration_tests" ];
+  pytestFlagsArray = [
+    # Exclude tests that requires network features
+    "--ignore=integration_tests"
+  ];
 
   preCheck = ''
     export HOME=$(mktemp -d)
@@ -76,7 +76,9 @@ buildPythonPackage rec {
     "test_send_dict"
   ];
 
-  pythonImportsCheck = [ "slack" ];
+  pythonImportsCheck = [
+    "slack"
+  ];
 
   meta = with lib; {
     description = "A client for Slack, which supports the Slack Web API and Real Time Messaging (RTM) API";