diff --git a/v1/add.go b/v1/add.go
new file mode 100644
index 0000000..b4816f3
--- /dev/null
+++ b/v1/add.go
@@ -0,0 +1,5 @@
+package testmod
+
+func Add(a, b int) int {
+	return a + b
+}