diff --git a/stix2/test/test_external_reference.py b/stix2/test/test_external_reference.py
index 2b79f01..9b90998 100644
--- a/stix2/test/test_external_reference.py
+++ b/stix2/test/test_external_reference.py
@@ -42,7 +42,7 @@ def test_external_reference_capec():
     )
 
     assert str(ref) == CAPEC
-    assert re.match("ExternalReference\(source_name=u?'capec', external_id=u?'CAPEC-550'\)", repr(ref))
+    assert re.match("ExternalReference\\(source_name=u?'capec', external_id=u?'CAPEC-550'\\)", repr(ref))
 
 
 CAPEC_URL = """{
@@ -109,7 +109,7 @@ def test_external_reference_offline():
     )
 
     assert str(ref) == OFFLINE
-    assert re.match("ExternalReference\(source_name=u?'ACME Threat Intel', description=u?'Threat report'\)", repr(ref))
+    assert re.match("ExternalReference\\(source_name=u?'ACME Threat Intel', description=u?'Threat report'\\)", repr(ref))
     # Yikes! This works
     assert eval("stix2." + repr(ref)) == ref
 
diff --git a/stix2/test/test_malware.py b/stix2/test/test_malware.py
index 8c565cd..2228885 100644
--- a/stix2/test/test_malware.py
+++ b/stix2/test/test_malware.py
@@ -126,7 +126,7 @@ def test_parse_malware(data):
 
 
 def test_parse_malware_invalid_labels():
-    data = re.compile('\[.+\]', re.DOTALL).sub('1', EXPECTED_MALWARE)
+    data = re.compile('\\[.+\\]', re.DOTALL).sub('1', EXPECTED_MALWARE)
     with pytest.raises(ValueError) as excinfo:
         stix2.parse(data)
     assert "Invalid value for Malware 'labels'" in str(excinfo.value)
diff --git a/stix2/test/test_pattern_expressions.py b/stix2/test/test_pattern_expressions.py
index 363458a..74a7d0f 100644
--- a/stix2/test/test_pattern_expressions.py
+++ b/stix2/test/test_pattern_expressions.py
@@ -319,13 +319,13 @@ def test_invalid_binary_constant():
 
 def test_escape_quotes_and_backslashes():
     exp = stix2.MatchesComparisonExpression("file:name",
-                                            "^Final Report.+\.exe$")
+                                            "^Final Report.+\\.exe$")
     assert str(exp) == "file:name MATCHES '^Final Report.+\\\\.exe$'"
 
 
 def test_like():
     exp = stix2.LikeComparisonExpression("directory:path",
-                                         "C:\Windows\%\\foo")
+                                         "C:\\Windows\\%\\foo")
     assert str(exp) == "directory:path LIKE 'C:\\\\Windows\\\\%\\\\foo'"
 
 
diff --git a/tox.ini b/tox.ini
index ac4e89f..86cd4ee 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,py34,py35,py36,pycodestyle,isort-check
+envlist = py27,py34,py35,py36,style,isort-check
 
 [testenv]
 deps =
@@ -10,22 +10,17 @@ deps =
     coverage
     taxii2-client
 commands =
-    py.test --ignore=stix2/test/test_workbench.py --cov=stix2 stix2/test/ --cov-report term-missing
-    py.test stix2/test/test_workbench.py --cov=stix2 --cov-report term-missing --cov-append
+    pytest --ignore=stix2/test/test_workbench.py --cov=stix2 stix2/test/ --cov-report term-missing
+    pytest stix2/test/test_workbench.py --cov=stix2 --cov-report term-missing --cov-append
 
 passenv = CI TRAVIS TRAVIS_*
 
-[testenv:pycodestyle]
+[testenv:style]
 deps =
   flake8
-  pycodestyle
 commands =
-  pycodestyle ./stix2
   flake8
 
-[pycodestyle]
-max-line-length=160
-
 [flake8]
 max-line-length=160
 
@@ -37,7 +32,7 @@ commands =
 
 [travis]
 python =
-  2.7: py27, pycodestyle
-  3.4: py34, pycodestyle
-  3.5: py35, pycodestyle
-  3.6: py36, pycodestyle
+  2.7: py27, style
+  3.4: py34, style
+  3.5: py35, style
+  3.6: py36, style