diff --git a/lib/bindings.js b/lib/bindings.js
index <HASH>..<HASH> 100644
--- a/lib/bindings.js
+++ b/lib/bindings.js
@@ -14,7 +14,8 @@ export function bindStyle(node, properties){
 export function bindClass(node, classes){
     // convert classes into an array
     const classList = new Constraint(() => {
-        const classesVal = classes.get();
+        const classesVal = classes instanceof Constraint ? classes.get()
+                                                         : classes;
         if(typeof classesVal === "string"){
             // split the string into words
             return classesVal.match(/\S+/g);
classBinding now supports non-constraint values.