diff --git a/pisi-spec.rng b/pisi-spec.rng
index 107d7377..b5a539c0 100644
--- a/pisi-spec.rng
+++ b/pisi-spec.rng
@@ -62,6 +62,9 @@
             <optional>
                 <ref name="License"/>
             </optional>
+            <optional>
+                <ref name="Icon"/>
+            </optional>
             <zeroOrMore>
                 <ref name="IsA"/>
             </zeroOrMore>