diff --git a/ymod/go.mod b/ymod/go.mod
new file mode 100644
index 0000000..6c9fd8e
--- /dev/null
+++ b/ymod/go.mod
@@ -0,0 +1,3 @@
+module git.alienyuki.com/yuki/hellogomod/ymod
+
+go 1.24.4
diff --git a/ymod/ylib.go b/ymod/ylib.go
new file mode 100644
index 0000000..86761f7
--- /dev/null
+++ b/ymod/ylib.go
@@ -0,0 +1,5 @@
+package ylib
+
+func YHello() string {
+	return "Hello, yuki!"
+}