diff --git a/gulp/mod.js b/gulp/mod.js
index 87912bb3..1eb1692a 100644
--- a/gulp/mod.js
+++ b/gulp/mod.js
@@ -1,3 +1,15 @@
+/**
+ *
+ * @param {string} source
+ * @param {*} map
+ * @returns
+ */
 module.exports = function (source, map) {
-    return source + `\nexport let $s=(n,v)=>eval(n+"=v")`;
+    const regex = /export (?:let|class) (?<name>\w+)/g;
+    // @ts-ignore
+    [...source.matchAll(regex)]
+        .map(n => n.groups.name)
+        .forEach(name => (source += `export const $S_${name}=(v)=>${name}=v;\n`));
+
+    return source;
 };
diff --git a/src/js/mods/modloader.js b/src/js/mods/modloader.js
index 71a87131..e60156bf 100644
--- a/src/js/mods/modloader.js
+++ b/src/js/mods/modloader.js
@@ -79,7 +79,9 @@ export class ModLoader {
                             return module[member];
                         },
                         set(v) {
-                            module["$s"](member, v);
+                            let fun = module["$S_" + member];
+                            if (!fun) throw new TypeError(`Assignment to constant shapez export "${member}"`);
+                            fun(v);
                         },
                     });
                 }