diff --git a/tests/test_step.py b/tests/test_step.py
index 85e206f4..089fe710 100644
--- a/tests/test_step.py
+++ b/tests/test_step.py
@@ -461,12 +461,12 @@ def test_step_run_crds_values(step_class):
     step = step_class()
     step.process = lambda *args: None
 
-    assert step.str1 == 'default'
-    assert step._initialized['str1'] is False
+    assert step.str1 == "default"
+    assert step._initialized["str1"] is False
 
     step.run("science.fits")
-    assert step.str1 == 'from config'
-    assert step._initialized['str1'] is True
+    assert step.str1 == "from config"
+    assert step._initialized["str1"] is True
 
 
 @pytest.mark.usefixtures("_mock_crds_reffile")
@@ -476,12 +476,12 @@ def test_step_run_keyword_values(step_class):
     step = step_class()
     step.process = lambda *args: None
 
-    assert step.str1 == 'default'
-    assert step._initialized['str1'] is False
+    assert step.str1 == "default"
+    assert step._initialized["str1"] is False
 
-    step.run("science.fits", str1='from keywords')
-    assert step.str1 == 'from keywords'
-    assert step._initialized['str1'] is True
+    step.run("science.fits", str1="from keywords")
+    assert step.str1 == "from keywords"
+    assert step._initialized["str1"] is True
 
 
 @pytest.mark.usefixtures("_mock_crds_reffile")
@@ -491,10 +491,10 @@ def test_pipe_run_step_values():
     step.process = lambda *args: None
 
     # Step parameters are initialized when created via the pipeline
-    assert step.step1.str1 == 'default'
-    assert step.step1._initialized['str1'] is True
+    assert step.step1.str1 == "default"
+    assert step.step1._initialized["str1"] is True
 
     # Parameters in a step dictionary can still override them
-    step.run("science.fits", steps={'step1': {'str1': 'from steps'}})
-    assert step.step1.str1 == 'from steps'
-    assert step.step1._initialized['str1'] is True
+    step.run("science.fits", steps={"step1": {"str1": "from steps"}})
+    assert step.step1.str1 == "from steps"
+    assert step.step1._initialized["str1"] is True