diff --git a/pinaxcon/templatetags/lca2018_tags.py b/pinaxcon/templatetags/lca2018_tags.py
index 9ca36f2a..47456f6e 100644
--- a/pinaxcon/templatetags/lca2018_tags.py
+++ b/pinaxcon/templatetags/lca2018_tags.py
@@ -52,7 +52,7 @@ def speaker_photo(context, speaker, size):
             thumbnail = thumbnailer.get_thumbnail(thumbnail_options)
             return thumbnail.url
         except:
-            log.exception("Cannot create thumbnail for speaker %s, image %s" % speaker.code, speaker.photo)
+            log.exception("Cannot create thumbnail for speaker %s, image %s" % (speaker.code, speaker.photo))
 
     # Use gravatar if no photo can be used.
     email = speaker.user.email.encode("utf-8")