diff --git a/atreal_openads/models.py b/atreal_openads/models.py
index 86c06db..f2afafc 100644
--- a/atreal_openads/models.py
+++ b/atreal_openads/models.py
@@ -742,7 +742,7 @@ class AtrealOpenads(BaseResource, HTTPResource, BaseModel):
 
         # log files to be forwarded
         self.logger.debug("----- files (begining) -----")
-        self.logger.debug(files)
+        self.logger.debug("%r", files)
         self.logger.debug("----- files (end) -----")
 
         # make a request to openADS.API (with the payload)