diff --git a/src/execnet/gateway_base.py b/src/execnet/gateway_base.py
index 73dc7175..45debc16 100644
--- a/src/execnet/gateway_base.py
+++ b/src/execnet/gateway_base.py
@@ -1062,6 +1062,8 @@ def _finished_receiving(self) -> None:
 
 
 class ChannelFile:
+    encoding = "utf-8"
+
     def __init__(self, channel: Channel, proxyclose: bool = True) -> None:
         self.channel = channel
         self._proxyclose = proxyclose
diff --git a/testing/test_channel.py b/testing/test_channel.py
index d4712277..266a55ca 100644
--- a/testing/test_channel.py
+++ b/testing/test_channel.py
@@ -308,6 +308,11 @@ def f(item):
 
 
 class TestChannelFile:
+    def test_channel_file_encoding(self, gw: Gateway) -> None:
+        channel = gw.newchannel()
+        assert channel.makefile("r").encoding == "utf-8"
+        assert channel.makefile("w").encoding == "utf-8"
+
     def test_channel_file_write(self, gw: Gateway) -> None:
         channel = gw.remote_exec(
             """