diff --git a/lib/mixins/property-effects.html b/lib/mixins/property-effects.html
index cdcf0ed32a..2679b593c3 100644
--- a/lib/mixins/property-effects.html
+++ b/lib/mixins/property-effects.html
@@ -2533,6 +2533,9 @@
           // Attribute or property
           let origName = name;
           let kind = 'property';
+          // The only way we see a capital letter here is if the attr has
+          // a capital letter in it per spec. In this case, to make sure
+          // this binding works, we go ahead and make the binding to the attribute.
           if (capitalAttributeRegex.test(name)) {
             kind = 'attribute';
           } else if (name[name.length-1] == '$') {