diff --git a/backend/windmill-worker/src/js_eval.rs b/backend/windmill-worker/src/js_eval.rs
index 25703f943b..70966d7e09 100644
--- a/backend/windmill-worker/src/js_eval.rs
+++ b/backend/windmill-worker/src/js_eval.rs
@@ -683,8 +683,8 @@ import("file:///eval.ts").then((module) => module.main(...args)).then(JSON.strin
     let local = v8::Local::new(scope, global);
     // Deserialize a `v8` object into a Rust type using `serde_v8`,
     // in this case deserialize to a JSON `Value`.
-    let r = serde_v8::from_v8::<String>(scope, local)?;
-    Ok(unsafe_raw(r))
+    let r = serde_v8::from_v8::<Option<String>>(scope, local)?;
+    Ok(unsafe_raw(r.unwrap_or_else(|| "null".to_string())))
 }
 
 #[op]
diff --git a/backend/windmill-worker/src/runtime.js b/backend/windmill-worker/src/runtime.js
index 3bcd520025..8a23dc89a9 100644
--- a/backend/windmill-worker/src/runtime.js
+++ b/backend/windmill-worker/src/runtime.js
@@ -22,10 +22,15 @@ import "ext:deno_web/13_message_port.js";
 import "ext:deno_web/14_compression.js";
 import "ext:deno_web/15_performance.js";
 
+globalThis.atob = base64.atob;
+globalThis.btoa = base64.btoa;
 globalThis.fetch = fetch.fetch;
 globalThis.Request = request.Request;
 globalThis.Blob = file.Blob;
 globalThis.URL = url.URL;
+globalThis.FormData = formData.FormData;
+globalThis.URLSearchParams = url.URLSearchParams;
+globalThis.Headers = headers.Headers;
 globalThis.FileReader = fileReader.FileReader;
 globalThis.console = new console.Console((msg, level) =>
   globalThis.Deno.core.ops.op_log([msg])