diff --git a/src/js/datatypeCleanupJS.js b/src/js/datatypeCleanupJS.js
index d5a218fd570c3b6f868b34c0f03f1ef29af8fdad..0d7d0e0ee5ebfe3d028a6e22489b32ceb3c96402 100644
--- a/src/js/datatypeCleanupJS.js
+++ b/src/js/datatypeCleanupJS.js
@@ -2420,6 +2420,9 @@ App.Entity.Utils.RARuleDatatypeCleanup = function() {
 			if (k === 'assignment' || k === 'clothes' || k === 'label' || k === 'removeLabel' ) {
 				continue;
 			}
+			if (v[0] === undefined) {
+				continue;
+			}
 			if (v[0].toLowerCase() !== v[0]) {
 				set[k] = v.charAt(0).toLowerCase() + v.substr(1);
 			}