--- a/python/toolbox/logs.py
+++ b/python/toolbox/logs.py
@@ -4,7 +4,7 @@
 def has_duplicate(path):
     """True when any line occurs more than once. Each line is compared against a fresh pass over the file."""
     with open(path) as fp:
-        for line in fp.readlines():
+        for line in fp:
             fp.seek(0)
             if sum(1 for other in fp if other == line) > 1:
                 return True