diff --git a/.tool/go.mod b/.tool/go.mod
new file mode 100644
index 00000000..cfae70c1
--- /dev/null
+++ b/.tool/go.mod
@@ -0,0 +1,5 @@
+module github.com/opencontainers/distribution-spec/.tool
+
+go 1.15
+
+require github.com/opencontainers/distribution-spec/specs-go v0.0.0-20210623213441-eb171947459c // indirect