diff --git a/packages/sandbox/src/sandbox.js b/packages/sandbox/src/sandbox.js
index daffdee..c04ea9f 100644
--- a/packages/sandbox/src/sandbox.js
+++ b/packages/sandbox/src/sandbox.js
@@ -98,7 +98,6 @@ export default class Sandbox {
             console.error("evaluateAssignmentExpression(): Can't handle operator", node.operator);
             return undefined;
         }
-        return value;
       };
       if (Vasync) {
         return {
@@ -295,6 +294,19 @@ export default class Sandbox {
     return {value: invokeMember(O.value, P.value, args, callOptional, memberOptional)};
   }
 
+  evaluateConditionalExpression(node) {
+    const test = this.evaluate(node.test);
+    if (test.async) {
+      return {
+        async: true,
+        value: Promise.resolve(test.value).then((test) => (
+          this.evaluate(test ? node.consequent : node.alternate).value
+        )),
+      };
+    }
+    return this.evaluate(test.value ? node.consequent : node.alternate);
+  }
+
   // eslint-disable-next-line class-methods-use-this
   evaluateDirectiveLiteral({value}) {
     return {value};
@@ -560,6 +572,7 @@ export default class Sandbox {
       'AwaitExpression',
       'BinaryExpression',
       'CallExpression',
+      'ConditionalExpression',
       'DirectiveLiteral',
       'Identifier',
       'Literal',