diff --git a/pubs/repo.py b/pubs/repo.py
index 6aac55a..e3df89e 100644
--- a/pubs/repo.py
+++ b/pubs/repo.py
@@ -20,7 +20,7 @@ class CiteKeyError(Exception):
         self.message = message
         self.citekey = citekey
 
-    def __repr__(self):
+    def __str__(self):
         return self.message or self.default_msg.format(self.citekey)
 
 
diff --git a/pubs/uis.py b/pubs/uis.py
index 1392050..f61feb3 100644
--- a/pubs/uis.py
+++ b/pubs/uis.py
@@ -87,7 +87,7 @@ class PrintUI(object):
         if self.debug:
             raise exc
         else:
-            self.error(exc)
+            self.error(exc.__string__())
             self.exit()