diff --git a/src/allmydata/util/eliotutil.py b/src/allmydata/util/eliotutil.py
index f2272a731..fe431568f 100644
--- a/src/allmydata/util/eliotutil.py
+++ b/src/allmydata/util/eliotutil.py
@@ -335,12 +335,7 @@ def log_call_deferred(action_type):
             kwargs = {k: bytes_to_unicode(True, kw[k]) for k in kw}
             # Remove complex (unserializable) objects from positional args to
             # prevent eliot from throwing errors when it attempts serialization
-            args = tuple(
-                a[pos]
-                if is_json_serializable(a[pos])
-                else str(a[pos])
-                for pos in range(len(a))
-            )
+            args = tuple(arg if is_json_serializable(arg) else str(arg) for arg in a)
             with start_action(action_type=action_type, args=args, kwargs=kwargs).context():
                 # Use addActionFinish so that the action finishes when the
                 # Deferred fires.