diff --git a/python_terraform/__init__.py b/python_terraform/__init__.py
index 4e0ff7d..f8d769d 100644
--- a/python_terraform/__init__.py
+++ b/python_terraform/__init__.py
@@ -396,7 +396,7 @@ class VariableFiles(object):
         self.files = []
 
     def create(self, variables):
-        with tempfile.NamedTemporaryFile('w+t', delete=False) as temp:
+        with tempfile.NamedTemporaryFile('w+t', suffix='.tfvars.json', delete=False) as temp:
             log.debug('{0} is created'.format(temp.name))
             self.files.append(temp)
             log.debug(