diff --git a/contrib/chg/Makefile b/contrib/chg/Makefile
--- a/contrib/chg/Makefile
+++ b/contrib/chg/Makefile
@@ -38,7 +38,6 @@ serve:
 	$(HG) serve --cwd / --cmdserver chgunix \
 		--address $(CHGSOCKNAME) \
 		--config extensions.chgserver= \
-		--config progress.assume-tty=1 \
 		--config cmdserver.log=/dev/stderr
 
 .PHONY: clean
diff --git a/contrib/chg/chg.c b/contrib/chg/chg.c
--- a/contrib/chg/chg.c
+++ b/contrib/chg/chg.c
@@ -216,8 +216,6 @@ static void execcmdserver(const struct c
 		"--daemon-postexec", "none",
 		"--pid-file", opts->pidfile,
 		"--config", "extensions.chgserver=",
-		/* wrap root ui so that it can be disabled/enabled by config */
-		"--config", "progress.assume-tty=1",
 	};
 	size_t baseargvsize = sizeof(baseargv) / sizeof(baseargv[0]);
 	size_t argsize = baseargvsize + opts->argsize + 1;
diff --git a/hgext/chgserver.py b/hgext/chgserver.py
--- a/hgext/chgserver.py
+++ b/hgext/chgserver.py
@@ -582,8 +582,6 @@ class AutoExitMixIn:  # use old-style to
 
 class chgunixservice(commandserver.unixservice):
     def init(self):
-        # drop options set for "hg serve --cmdserver" command
-        self.ui.setconfig('progress', 'assume-tty', None)
         signal.signal(signal.SIGHUP, self._reloadconfig)
         self._inithashstate()
         class cls(AutoExitMixIn, SocketServer.ForkingMixIn,