diff --git a/.luacheckrc b/.luacheckrc
new file mode 100644
index 0000000..5ee1cab
--- /dev/null
+++ b/.luacheckrc
@@ -0,0 +1,25 @@
+std = "lua51+minetest"
+unused_args = false
+allow_defined_top = true
+max_line_length = 999
+
+stds.minetest = {
+	read_globals = {
+		"minetest",
+		"VoxelManip",
+		"VoxelArea",
+		"PseudoRandom",
+		"ItemStack",
+		"default",
+		table = {
+			fields = {
+				"copy",
+			},
+		},
+	}
+}
+
+read_globals = {
+	"pipeworks",
+}
+
diff --git a/utils/formspec.lua b/utils/formspec.lua
index 8e089ab..073c49c 100644
--- a/utils/formspec.lua
+++ b/utils/formspec.lua
@@ -1,4 +1,5 @@
 function generate(size)
+	local cfg
 	if size == "small" then
 		cfg = {
 			window_width = 8,