diff --git a/fmn/lib/__init__.py b/fmn/lib/__init__.py
index <HASH>..<HASH> 100644
--- a/fmn/lib/__init__.py
+++ b/fmn/lib/__init__.py
@@ -86,6 +86,8 @@ def matches(filter, message, valid_paths, rule_cache, config):
                 return False
         except Exception as e:
             log.exception(e)
+            # If something throws an exception then we do *not* have a match.
+            return False
 
     # Then all rules matched on this filter..
     return True
If a rule throws an exception, then the match should fail.

This even happens sporadically, sometimes when FAS is unavailable and
the app needs to query FAS to figure out whose IRC nick is whose.

This should fix fedora-infra/fmn#<I> (at least, it is one of possibly
many causes).