diff --git a/core-selector.html b/core-selector.html
index 0035319..9e5b7f1 100644
--- a/core-selector.html
+++ b/core-selector.html
@@ -245,6 +245,9 @@
       },
 
       get items() {
+        if (!this.target) {
+          return [];
+        }
         var nodes = this.target !== this ? (this.itemsSelector ? 
             this.target.querySelectorAll(this.itemsSelector) : 
                 this.target.children) : this.$.items.getDistributedNodes();
@@ -257,10 +260,12 @@
         if (old) {
           this.removeListener(old);
           this.observer.disconnect();
+          this.clearSelection();
         }
         if (this.target) {
           this.addListener(this.target);
           this.observer.observe(this.target, {childList: true});
+          this.updateSelected();
         }
       },