diff --git a/dotdrop/templategen.py b/dotdrop/templategen.py
index e532a5f..d1db7db 100644
--- a/dotdrop/templategen.py
+++ b/dotdrop/templategen.py
@@ -44,7 +44,8 @@ class Templategen:
                                comment_end_string=COMMENT_END)
         # adding variables
         self.env.globals['env'] = os.environ
-        self.env.globals.update(variables)
+        if variables:
+            self.env.globals.update(variables)
         # adding header method
         self.env.globals['header'] = self._header
         # adding helper methods
diff --git a/tests/test_compare.py b/tests/test_compare.py
index 7bb10be..6c24db4 100644
--- a/tests/test_compare.py
+++ b/tests/test_compare.py
@@ -46,6 +46,11 @@ class TestCompare(unittest.TestCase):
             results[path] = diff == ''
         return results
 
+    def test_none(self):
+        t = Templategen(base=self.CONFIG_DOTPATH,
+                        debug=True, variables=None)
+        self.assertTrue(t is not None)
+
     def test_compare(self):
         """Test the compare function"""
         # setup some directories