diff --git a/biblio-tools/v1/crossref/prefixes/expand.ini b/biblio-tools/v1/crossref/prefixes/expand.ini
index b10a93c..61664c0 100644
--- a/biblio-tools/v1/crossref/prefixes/expand.ini
+++ b/biblio-tools/v1/crossref/prefixes/expand.ini
@@ -14,6 +14,10 @@
 cacheName = prefixes
 
 [expand/assign]
+path = value
+value = get('value).split('/').filter(i=>i.match(/^10./)).pop()
+
+[expand/assign]
 path = url
 value = fix('https://api.crossref.org/prefixes', self.value).join('/')