diff --git a/src/lib/collection.html b/src/lib/collection.html
index 71cd691336..997b3a5f3a 100644
--- a/src/lib/collection.html
+++ b/src/lib/collection.html
@@ -50,9 +50,10 @@
     },
 
     removeKey: function(key) {
-      key = this._parseKey(key);
-      this._removeFromMap(this.store[key]);
-      delete this.store[key];
+      if (key = this._parseKey(key)) {
+        this._removeFromMap(this.store[key]);
+        delete this.store[key];
+      }
     },
 
     _removeFromMap: function(item) {
@@ -88,29 +89,30 @@
     },
 
     _parseKey: function(key) {
-      if (key[0] == '#') {
+      if (key && key[0] == '#') {
         return key.slice(1);
       }
-      throw new Error('unexpected key ' + key);
     },
 
     setItem: function(key, item) {
-      key = this._parseKey(key);
-      var old = this.store[key];
-      if (old) {
-        this._removeFromMap(old);
-      }
-      if (item && typeof item == 'object') {
-        this.omap.set(item, key);
-      } else {
-        this.pmap[item] = key;
+      if (key = this._parseKey(key)) {
+        var old = this.store[key];
+        if (old) {
+          this._removeFromMap(old);
+        }
+        if (item && typeof item == 'object') {
+          this.omap.set(item, key);
+        } else {
+          this.pmap[item] = key;
+        }
+        this.store[key] = item;
       }
-      this.store[key] = item;
     },
 
     getItem: function(key) {
-      key = this._parseKey(key);
-      return this.store[key];
+      if (key = this._parseKey(key)) {
+        return this.store[key];
+      }
     },
 
     getItems: function() {
diff --git a/src/standard/notify-path.html b/src/standard/notify-path.html
index 927f8403d4..328a6cbba9 100644
--- a/src/standard/notify-path.html
+++ b/src/standard/notify-path.html
@@ -85,7 +85,9 @@
         var info = {};
         this._get(path, this, info);
         // Notify change to key-based path
-        this._notifyPath(info.path, value, fromAbove);
+        if (info.path) {
+          this._notifyPath(info.path, value, fromAbove);
+        }
       },
 
       // Note: this implemetation only accepts key-based array paths