diff --git a/js/hydra.js b/js/hydra.js
index 69b273b..dd1bf2f 100644
--- a/js/hydra.js
+++ b/js/hydra.js
@@ -18,7 +18,7 @@
         return null;
       }
 
-      if (('rdfs:Class' !== type['@type']) && ('hydra:Class' !== type['@type'])) {
+      if (('rdfs:Class' !== type['@type']) && ('hydra:Class' !== type['@type']) && type.domain) {
         type = this.getElementDefinition(type.domain);
       }