diff --git a/home/vim/plugin/settings/null-ls.lua b/home/vim/plugin/settings/null-ls.lua
index 8446683..af6d629 100644
--- a/home/vim/plugin/settings/null-ls.lua
+++ b/home/vim/plugin/settings/null-ls.lua
@@ -116,6 +116,8 @@ null_ls.register({
         -- Indent with 4 spaces, simplify the code, indent switch cases,
         -- add space after redirection, use POSIX
         extra_args = { "-i", "4", "-s", "-ci", "-sr", "-ln", "posix" },
+        -- Restrict to POSIX sh
+        filetypes = { "sh" },
         -- Only used if available
         condition = utils.is_executable_condition("shfmt"),
     }),