diff --git a/schema/edxml.rng b/schema/edxml.rng
index 1244e66eabed8dff8c4141c5eb214ea2203d7f15..309a8b9f9feb0946349d794bdc82224cb9cb72ff 100644
--- a/schema/edxml.rng
+++ b/schema/edxml.rng
@@ -688,7 +688,14 @@
     <define name="elem.ref">
         <element name="ref">
             <attribute name="target"/>
-            <text/>
+            <interleave>
+                <zeroOrMore>
+                    <ref name="elem.hi"/>
+                </zeroOrMore>
+                <zeroOrMore>
+                    <text/>
+                </zeroOrMore>
+            </interleave>
         </element>
     </define>