diff --git a/packages/behavior/compilers.hooks.js b/packages/behavior/compilers.hooks.js
index 3df78ad..1f2314b 100644
--- a/packages/behavior/compilers.hooks.js
+++ b/packages/behavior/compilers.hooks.js
@@ -40,6 +40,9 @@ function disambiguateResult(value, fn) {
 }
 
 function compileExpression(expression) {
+  if (0 === expression.ops.length) {
+    return () => undefined;
+  }
   const assign = 'undefined' !== typeof expression.assign
     ? compile(expression.assign)
     : undefined;