diff --git a/regress/cfg-client-lost.sh b/regress/cfg-client-lost.sh
new file mode 100755
index 000000000..4593576bd
--- /dev/null
+++ b/regress/cfg-client-lost.sh
@@ -0,0 +1,41 @@
+#!/bin/sh
+
+PATH=/bin:/usr/bin
+TERM=screen
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+
+TMPDIR=$(mktemp -d) || exit 1
+TMUX="$TEST_TMUX -S$TMPDIR/tmux.sock"
+CONF="$TMPDIR/tmux.conf"
+READY="$TMPDIR/ready"
+
+cleanup()
+{
+	$TMUX kill-server 2>/dev/null
+	rm -rf "$TMPDIR"
+}
+trap cleanup 0 1 15
+
+cat <<EOF >$CONF
+new-session -d -s keep 'sleep 1000'
+run-shell -b 'touch $READY'
+run-shell -d 1 true
+source-file /dev/null
+EOF
+
+$TMUX -f$CONF new-session -d -s client 'sleep 100' &
+pid=$!
+i=0
+while [ ! -f "$READY" ]; do
+	[ "$i" -eq 50 ] && exit 1
+	i=$((i + 1))
+	sleep 0.1
+done
+kill "$pid" 2>/dev/null
+wait "$pid" 2>/dev/null
+
+sleep 2
+$TMUX has-session -t keep || exit 1
+
+exit 0