diff --git a/calculon-0.1-1.rockspec b/calculon-0.1-1.rockspec
index 712a492..26d7b69 100644
--- a/calculon-0.1-1.rockspec
+++ b/calculon-0.1-1.rockspec
@@ -11,5 +11,10 @@ build = {
    type = "builtin",
    modules = {
       calculon = "build/calculon/init.lua"
+   },
+   install = {
+      lua = {
+         calculon = "calculon.d.tl"
+      }
    }
 }
diff --git a/calculon.d.tl b/calculon.d.tl
new file mode 100644
index 0000000..22a6abe
--- /dev/null
+++ b/calculon.d.tl
@@ -0,0 +1,5 @@
+local record calculon
+  add: function(a: number, b: number): number
+end
+
+return calculon
\ No newline at end of file