diff --git a/docs/schemas/storagepool.rng b/docs/schemas/storagepool.rng
index 9c528175bd3b8b8cdf6bc7bb8657ca4dd7c49ecf..3a61f04db4343a374934eb64b93a3bab7de112bd 100644
--- a/docs/schemas/storagepool.rng
+++ b/docs/schemas/storagepool.rng
@@ -412,7 +412,7 @@
       <element name='format'>
         <attribute name='type'>
           <choice>
-            <value>none</value>
+            <value>unknown</value>
             <value>dos</value>
             <value>dvh</value>
             <value>gpt</value>