diff --git a/master.cfg b/master.cfg
index 0bf54e9..871bf4f 100644
--- a/master.cfg
+++ b/master.cfg
@@ -579,7 +579,7 @@ class LookupEmailTryBuild (object):
         for directory, sort_order in tryjobdir:
             for _, _, filenames in os.walk (directory):
                 for f in sorted (filenames, reverse = sort_order):
-                    with open (f, 'r') as myf:
+                    with open (os.path.join (directory, f), 'r') as myf:
                         for line in reversed (myf.readlines ()):
                             m = re.match (name_re, line)
                             if m: