diff --git a/src/eval.js b/src/eval.js
index 7766884..a20794d 100644
--- a/src/eval.js
+++ b/src/eval.js
@@ -269,19 +269,13 @@ export const eval_modules = (
 
   // TODO bug if module imported twice, once as external and as regular
 
-  patch_promise(globalThis.run_window)
-
   const is_async = has_toplevel_await(parse_result.modules)
 
-  const codestring = 
-    `
+  const codestring = `
+
     let children, prev_children
 
-    // TODO refactor, move patch_promise here
-    globalThis.get_children = () => children
-    globalThis.set_children = (_children) => children = _children
-
-    // TODO use native array for stack for perf?
+    // TODO use native array for stack for perf? stack contains booleans
     const stack = new Array() 
 
     let logs = []
@@ -296,6 +290,44 @@ export const eval_modules = (
     let is_recording_deferred_calls
     let is_toplevel_call = true
 
+    let promise_then
+
+    function apply_promise_patch() {
+
+      promise_then = Promise.prototype.then
+
+      Promise.prototype.then = function then(on_resolve, on_reject) {
+        if(children == null) {
+          children = []
+        }
+        let children_copy = children
+
+        const make_callback = cb => cb == null
+          ? null
+          : value => {
+              const current = children
+              children = children_copy
+              try {
+                return cb(value)
+              } finally {
+                children = current
+              }
+            }
+
+        return promise_then.call(
+          this,
+          make_callback(on_resolve),
+          make_callback(on_reject),
+        )
+      }
+    }
+
+    function remove_promise_patch() {
+      Promise.prototype.then = promise_then
+    }
+
+    apply_promise_patch()
+
     const set_record_call = () => {
       for(let i = 0; i < stack.length; i++) {
         stack[i] = true
@@ -634,6 +666,7 @@ export const eval_modules = (
            const _logs = logs
            logs = []
            children = null
+           remove_promise_patch()
            return { modules: __modules, calltree: current_call, logs: _logs }
          }
         `
@@ -645,6 +678,7 @@ export const eval_modules = (
       const _logs = logs
       logs = []
       children = null
+      remove_promise_patch()
       return { modules: __modules, calltree: current_call, logs: _logs }
     }
 
diff --git a/src/patch_promise.js b/src/patch_promise.js
deleted file mode 100644
index 6b66635..0000000
--- a/src/patch_promise.js
+++ /dev/null
@@ -1,37 +0,0 @@
-export const patch_promise = window => {
-
-  if(window.Promise.__patched) {
-    // already patched
-    return
-  }
-
-  const _then = window.Promise.prototype.then
-
-  window.Promise.prototype.then = function then(on_resolve, on_reject) {
-    let children = window.get_children()
-    if(children == null) {
-      children = []
-      window.set_children(children)
-    }
-
-    const make_callback = cb => cb == null
-      ? null
-      : value => {
-          const current = window.get_children()
-          window.set_children(children)
-          try {
-            return cb(value)
-          } finally {
-            window.set_children(current)
-          }
-        }
-
-    return _then.call(
-      this,
-      make_callback(on_resolve),
-      make_callback(on_reject),
-    )
-  }
-
-  window.Promise.__patched = true
-}
diff --git a/src/unwrap_promises.js b/src/unwrap_promises.js
deleted file mode 100644
index 3f140aa..0000000
--- a/src/unwrap_promises.js
+++ /dev/null
@@ -1,59 +0,0 @@
-export const unwrap_settled_promises = calltree => {
-  let is_finished = false
-
-  const unwrap = call => {
-    // TODO use run_window.Promise
-
-    if(!call.ok) {
-      return
-    }
-
-    if(call.value instanceof Promise) {
-      call.value
-        .then(value => {
-          if(is_finished) {
-            return
-          }
-          call.unwrapped_value = {ok: true, value}
-        })
-        .catch(error => {
-          if(is_finished) {
-            return
-          }
-          call.unwrapped_value = {ok: false, error}
-        })
-    }
-  }
-
-  const unwrap_tree = call => {
-    unwrap(call)
-    if(call.children != null) {
-      for(let c of call.children) {
-        unwrap(c)
-      }
-    }
-  }
-
-  unwrap_tree(calltree)
-
-  return Promise.resolve().then(() => {
-    is_finished = true
-    return calltree
-  })
-}
-
-/*
-const delay = new Promise(resolve => setTimeout(() => resolve('123'), 1000))
-
-const tree = {
-  value: Promise.resolve('resolved'),
-  ok: true,
-  children: [
-    {value: delay, ok: true}
-  ]
-}
-
-await unwrap_settled_promises(tree)
-console.log('tree', tree)
-*/
-