diff --git a/docs/specification.mdx b/docs/specification.mdx
index a45ead3..20cf9f6 100644
--- a/docs/specification.mdx
+++ b/docs/specification.mdx
@@ -59,7 +59,7 @@ metadata:
 
 The required `name` field:
 - Must be 1-64 characters
-- May only contain unicode lowercase alphanumeric characters (`a-z`) and hyphens (`-`)
+- May only contain unicode lowercase alphanumeric characters (`a-z`, `0-9`) and hyphens (`-`)
 - Must not start or end with a hyphen (`-`)
 - Must not contain consecutive hyphens (`--`)
 - Must match the parent directory name