diff --git a/src/allmydata/test/__init__.py b/src/allmydata/test/__init__.py
index ad245ca77..bca4a4ebf 100644
--- a/src/allmydata/test/__init__.py
+++ b/src/allmydata/test/__init__.py
@@ -125,5 +125,5 @@ if sys.platform == "win32":
     initialize()
 
 from eliot import to_file
-from allmydata.util.eliotutil import eliot_json_encoder
-to_file(open("eliot.log", "wb"), encoder=eliot_json_encoder)
+from allmydata.util.eliotutil import BytesEliotJSONEncoder
+to_file(open("eliot.log", "wb"), encoder=BytesEliotJSONEncoder)
diff --git a/src/allmydata/test/eliotutil.py b/src/allmydata/test/eliotutil.py
index bdc779f1d..8a2f63203 100644
--- a/src/allmydata/test/eliotutil.py
+++ b/src/allmydata/test/eliotutil.py
@@ -29,6 +29,7 @@ from eliot import (
     ILogger,
 )
 from eliot.testing import (
+    MemoryLogger,
     swap_logger,
     check_for_errors,
 )
@@ -38,7 +39,7 @@ from twisted.python.monkey import (
 )
 
 from ..util.eliotutil import (
-    MemoryLogger,
+    BytesEliotJSONEncoder
 )
 
 _NAME = Field.for_types(
@@ -146,7 +147,7 @@ def with_logging(
     """
     @wraps(test_method)
     def run_with_logging(*args, **kwargs):
-        validating_logger = MemoryLogger()
+        validating_logger = MemoryLogger(encoder=BytesEliotJSONEncoder)
         original = swap_logger(None)
         try:
             swap_logger(_TwoLoggers(original, validating_logger))
diff --git a/src/allmydata/util/eliotutil.py b/src/allmydata/util/eliotutil.py
index b574f0def..ec417991c 100644
--- a/src/allmydata/util/eliotutil.py
+++ b/src/allmydata/util/eliotutil.py
@@ -3,17 +3,6 @@ Tools aimed at the interaction between Tahoe-LAFS implementation and Eliot.
 
 Ported to Python 3.
 """
-from __future__ import absolute_import
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-
-from __future__ import (
-    unicode_literals,
-    print_function,
-    absolute_import,
-    division,
-)
 
 __all__ = [
     "MemoryLogger",
@@ -26,11 +15,6 @@ __all__ = [
     "capture_logging",
 ]
 
-from future.utils import PY2
-if PY2:
-    from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
-from six import ensure_text
-
 from sys import (
     stdout,
 )
@@ -42,6 +26,7 @@ from logging import (
 )
 from json import loads
 
+from six import ensure_text
 from zope.interface import (
     implementer,
 )
@@ -65,7 +50,7 @@ from eliot.testing import (
     MemoryLogger,
     capture_logging,
 )
-from eliot.json import EliotJSONEncoder as eliot_json_encoder
+from eliot.json import EliotJSONEncoder
 
 from eliot._validation import (
     ValidationError,
@@ -94,6 +79,15 @@ from twisted.internet.defer import (
 from twisted.application.service import Service
 
 
+class BytesEliotJSONEncoder(EliotJSONEncoder):
+    """Support encoding bytes."""
+
+    def default(self, o):
+        if isinstance(o, bytes):
+            return o.decode("utf-8", "backslashreplace")
+        return EliotJSONEncoder.default(self, o)
+
+
 def validateInstanceOf(t):
     """
     Return an Eliot validator that requires values to be instances of ``t``.
@@ -310,7 +304,7 @@ class _DestinationParser(object):
                     rotateLength=rotate_length,
                     maxRotatedFiles=max_rotated_files,
                 )
-        return lambda reactor: FileDestination(get_file(), eliot_json_encoder)
+        return lambda reactor: FileDestination(get_file(), encoder=BytesEliotJSONEncoder)
 
 
 _parse_destination_description = _DestinationParser().parse