diff --git a/tests/test_correct_year.py b/tests/test_correct_year.py
index 7a156cbf2..2c2f0d812 100644
--- a/tests/test_correct_year.py
+++ b/tests/test_correct_year.py
@@ -16,10 +16,10 @@ from util import TestApp
 def test_correct_year():
     try:
         # save current value of SOURCE_DATE_EPOCH
-        sde = os.environ.pop('SOURCE_DATE_EPOCH',None)
+        sde = os.environ.pop('SOURCE_DATE_EPOCH', None)
 
         # test with SOURCE_DATE_EPOCH unset: no modification
-        app = TestApp(buildername='html',testroot='correct-year')
+        app = TestApp(buildername='html', testroot='correct-year')
         app.builder.build_all()
         content = (app.outdir / 'contents.html').text()
         app.cleanup()
@@ -28,14 +28,14 @@ def test_correct_year():
         # test with SOURCE_DATE_EPOCH set: copyright year should be
         # updated
         os.environ['SOURCE_DATE_EPOCH'] = "1293840000"
-        app = TestApp(buildername='html',testroot='correct-year')
+        app = TestApp(buildername='html', testroot='correct-year')
         app.builder.build_all()
         content = (app.outdir / 'contents.html').text()
         app.cleanup()
         assert '2006-2011' in content
 
         os.environ['SOURCE_DATE_EPOCH'] = "1293839999"
-        app = TestApp(buildername='html',testroot='correct-year')
+        app = TestApp(buildername='html', testroot='correct-year')
         app.builder.build_all()
         content = (app.outdir / 'contents.html').text()
         app.cleanup()
@@ -43,7 +43,7 @@ def test_correct_year():
 
     finally:
         # Restores SOURCE_DATE_EPOCH
-        if sde == None:
-            os.environ.pop('SOURCE_DATE_EPOCH',None)
+        if sde is None:
+            os.environ.pop('SOURCE_DATE_EPOCH', None)
         else:
             os.environ['SOURCE_DATE_EPOCH'] = sde