diff --git a/js-runtime/src/js-runtime.js b/js-runtime/src/js-runtime.js
index 4d1ae9ff..9b0096cf 100644
--- a/js-runtime/src/js-runtime.js
+++ b/js-runtime/src/js-runtime.js
@@ -78,7 +78,7 @@ const zig = {
     this.wasm = wasm;
 
     values = [];
-    value_map = [];
+    value_map = {};
     this.addValue(globalThis);
   },