diff --git a/snippets/migration/index.js b/snippets/migration/index.js
index ca4b259..1f6a143 100644
--- a/snippets/migration/index.js
+++ b/snippets/migration/index.js
@@ -47,8 +47,8 @@ function assert (folder, args) {
       reason: 'name is not a string'
     },
     {
-      f:      () => ((/^(?:[0-9]+-[a-z]+|csv)$/iu).test (args[0])),
-      reason: 'name has to match /^[0-9]+-[a-z]+$/'
+      f:      () => ((/^(?:[0-9]+[-_][a-z-_]+|csv)$/iu).test (args[0])),
+      reason: 'name has to match /^[0-9]+[-_][a-z-_]+$/'
     },
     {
       f:      () => (typeof folder === 'string'),