diff --git a/rattail_fabric/core.py b/rattail_fabric/core.py
index f409f15..0cf8a9e 100644
--- a/rattail_fabric/core.py
+++ b/rattail_fabric/core.py
@@ -137,10 +137,14 @@ def upload_mako_template(local_path, remote_path, context={}, encoding='utf_8',
     """
     template = Template(filename=local_path)
 
+    # make copy of context; add env to it
+    context = dict(context)
+    context['env'] = env
+
     temp_dir = tempfile.mkdtemp(prefix='rattail-fabric.')
     temp_path = os.path.join(temp_dir, os.path.basename(local_path))
     with open(temp_path, 'wb') as f:
-        text = template.render(env=env, **context)
+        text = template.render(**context)
         f.write(text.encode(encoding))
     os.chmod(temp_path, os.stat(local_path).st_mode)