diff --git a/.luacheckrc b/.luacheckrc
new file mode 100644
index 0000000..3d1d1e8
--- /dev/null
+++ b/.luacheckrc
@@ -0,0 +1,17 @@
+-- Rerun tests only if their modification time changed.
+cache = true
+
+-- Glorious list of warnings: https://luacheck.readthedocs.io/en/stable/warnings.html
+ignore = {
+  "212", -- Unused argument, In the case of callback function, _arg_name is easier to understand than _, so this option is set to off.
+  "411", -- Redefining a local variable.
+  "412", -- Redefining an argument.
+  "422", -- Shadowing an argument
+  "122", -- Indirectly setting a readonly global
+  "331"  -- Value assigned to variable is mutated but never accessed
+}
+
+-- Global objects defined by the C code
+read_globals = {
+  "vim",
+}
diff --git a/lua/treesitter-matchup/internal.lua b/lua/treesitter-matchup/internal.lua
index 23a277b..8ee457c 100644
--- a/lua/treesitter-matchup/internal.lua
+++ b/lua/treesitter-matchup/internal.lua
@@ -86,7 +86,7 @@ function M.get_active_nodes(bufnr)
 end
 
 function M.containing_scope(node, bufnr, key)
-  local bufnr = bufnr or api.nvim_get_current_buf()
+  bufnr = bufnr or api.nvim_get_current_buf()
 
   local scopes = M.get_scopes(bufnr)
   if not node or not scopes then return end