diff --git a/Utilities/JsonUtils/checkLint.py b/Utilities/JsonUtils/checkLint.py
index fdd1fef0..dc37fe1e 100644
--- a/Utilities/JsonUtils/checkLint.py
+++ b/Utilities/JsonUtils/checkLint.py
@@ -1,10 +1,11 @@
 import json
+import sys
 
 
 def check(filename):
     try:
-        with open(filename) as f:
-            lf = json.load(f)
+        with open(filename) as fid:
+            json.load(fid)
             return True
     except:
         return False
diff --git a/Utilities/JsonUtils/resolveFileInputJson.py b/Utilities/JsonUtils/resolveFileInputJson.py
index b9da4c6e..50468abf 100644
--- a/Utilities/JsonUtils/resolveFileInputJson.py
+++ b/Utilities/JsonUtils/resolveFileInputJson.py
@@ -3,7 +3,7 @@
 
 
 def resolveFileInputJson(battmoDir, jsoninput):
-    if type(jsoninput) is dict:
+    if isinstance(jsoninput, dict):
         if "isFile" in jsoninput:
             filename = jsoninput["filename"]
             fullfilename = os.path.join(battmoDir, filename)
diff --git a/Utilities/JsonUtils/validateJsonFiles.m b/Utilities/JsonUtils/validateJsonFiles.m
index 461c29de..8728789b 100644
--- a/Utilities/JsonUtils/validateJsonFiles.m
+++ b/Utilities/JsonUtils/validateJsonFiles.m
@@ -1,4 +1,4 @@
-function is_valid = validateJsonFiles(jsonfiles)
+function isValid = validateJsonFiles(jsonfiles)
 
     if ~iscell(jsonfiles)
         jsonfiles = {jsonfiles};
@@ -14,17 +14,16 @@
         jsonfile = jsonfiles{k};
         dispif(mrstVerbose, 'Validating %s\n', jsonfile);
         try
-            %is_valid{k} = py.(modname).validate(battmoDir(), jsonfile); %#ok
-            py.(modname).validate(battmoDir(), jsonfile); %#ok
+            isValid{k} = py.(modname).validate(battmoDir(), jsonfile); %#ok
         catch e
             disp(e);
             error('Error when running the validation');
         end
-        assert(is_valid{k}, 'jsonfile %s is not valid', jsonfile);
+        assert(isValid{k}, 'jsonfile %s is not valid', jsonfile);
     end
 
     if numel(jsonfiles) == 1
-        is_valid = is_valid{1};
+        isValid = isValid{1};
     end
 
 end