diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..12304f4
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,5 @@
+module github.com/andoma-go/fastxor
+
+go 1.20
+
+require golang.org/x/sys v0.8.0
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..c5eb700
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=
+golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=