diff --git a/library/configfile.py b/library/configfile.py
index 1336c54..9a70fa0 100644
--- a/library/configfile.py
+++ b/library/configfile.py
@@ -48,7 +48,7 @@ def run_configfile_module():
     changed = False
 
     with open(path, 'r') as input:
-        with tempfile.NamedTemporaryFile(dir=os.path.dirname(path), mode="rw") as temp:
+        with tempfile.NamedTemporaryFile(dir=os.path.dirname(path), mode="w") as temp:
             for line in input:
                 print(expand(line), end=' ', file=temp)