diff --git a/lib/mixins/properties-changed.html b/lib/mixins/properties-changed.html
index 203874d523..bd47e08c73 100644
--- a/lib/mixins/properties-changed.html
+++ b/lib/mixins/properties-changed.html
@@ -337,6 +337,7 @@
           const old = this.__dataOld;
           if (this._shouldPropertiesChange(props, changedProps, old)) {
             this.__dataPending = null;
+            this.__dataOld = null;
             this._propertiesChanged(props, changedProps, old);
           }
         }