diff --git a/civicrmapi4/civicrmapi4.py b/civicrmapi4/civicrmapi4.py
index 62b0082..6efcc2e 100644
--- a/civicrmapi4/civicrmapi4.py
+++ b/civicrmapi4/civicrmapi4.py
@@ -6,12 +6,11 @@ import logging
 
 from typing import List, Optional, Dict, Union
 
-from bs4 import BeautifulSoup
-
 
 log = logging.getLogger(__name__)
 
 
+#
 # TODOs and FIXMEs
 #
 # * come up with a better way to specify `where` clauses.
@@ -75,7 +74,7 @@ class APIv4:
         """
         self.session = requests.Session()
 
-        ### Perform login post
+        # Perform login post
         self.session.cookies.update({"has_js": "1"})
         postdata = {
             "name": user,
@@ -118,7 +117,7 @@ class APIv4:
 
         url = self.api_url+'/'+objName+'/'+action
         if params:
-            result = self.session.post(url, params={'params':json.dumps(params)}, data="")
+            result = self.session.post(url, params={'params': json.dumps(params)}, data="")
         else:
             result = self.session.post(url, data="")
         if (not result.ok):
@@ -188,7 +187,11 @@ class APIv4:
 
         return [x["name"] for x in ent]
 
-    def get(self, objName: str, where: Optional[List]=None, limit: Optional[int]=None, select=Optional[List[str]]) -> List:
+    def get(self,
+            objName: str,
+            where: Optional[List] = None,
+            limit: Optional[int] = None,
+            select=Optional[List[str]]) -> List:
         """
         Get objects based on a where clause, optional limit and optional field list.
 
@@ -207,7 +210,7 @@ class APIv4:
             params["limit"] = limit
         if where is not None:
             params["where"] = where
-        if columns is not None and columns:
+        if select is not None and select:
             params["select"] = select
 
         return self.call_values(objName, "get", params=params)
diff --git a/pyproject.toml b/pyproject.toml
index 118495b..4d957ae 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,3 +1,3 @@
 [build-system]
 requires = ["setuptools", "wheel"]
-build-backend = "setuptools-build_meta"
+
diff --git a/tox.ini b/tox.ini
index 7507b81..bd91f61 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,3 +1,15 @@
+[tox]
+envlist = py36, py37, py38, py39
+
+[testenv]
+deps =
+  flake8
+  mypy
+commands =
+  flake8
+  mypy civicrmapi4
+
+
 [flake8]
 max-line-length = 120
 max-complexity = 20