diff --git a/runtime/syntax/testdir/input/sh_13.sh b/runtime/syntax/testdir/input/sh_13.sh
new file mode 100644
index 0000000..a81c0a4
--- /dev/null
+++ b/runtime/syntax/testdir/input/sh_13.sh
@@ -0,0 +1,8 @@
+# Issue #17026 (bash highlighting requires space after $())
+# https://github.com/vim/vim/issues/17026#issuecomment-2774112284
+
+_comp_compgen_split -l -- "$(
+    tmux list-commands -F "#{command_list_name}"
+    tmux list-commands -F "#{command_list_alias}"
+)"
+