diff --git a/src/cmd.js b/src/cmd.js
index c683394..46505ed 100644
--- a/src/cmd.js
+++ b/src/cmd.js
@@ -216,6 +216,11 @@ const eval_modules_finished = (state, prev_state, result) => {
     return state
   }
 
+  if(result.rt_cxt.io_trace_is_replay_aborted) {
+    // execution was discarded, return state to execute `run_code` without io_trace
+    return clear_io_trace({...state, rt_cxt: result.rt_cxt})
+  }
+
   const next = find_call(
     apply_eval_result(state, result),
     current_cursor_position(state)
diff --git a/src/effects.js b/src/effects.js
index f49351e..e28db3e 100644
--- a/src/effects.js
+++ b/src/effects.js
@@ -7,7 +7,7 @@ import {
   get_deferred_calls
 } from './calltree.js'
 import {current_cursor_position} from './calltree.js'
-import {exec, FILES_ROOT} from './index.js'
+import {exec, reload_app_window, FILES_ROOT} from './index.js'
 
 // Imports in the context of `app_window`, so global variables in loaded
 // modules refer to that window's context 
@@ -209,7 +209,9 @@ export const apply_side_effects = (prev, next, ui) => {
         next.loading_external_imports_state != null
         ||
         next.eval_modules_state != null
-      if(is_loading) {
+      if(next.rt_cxt?.io_trace_is_replay_aborted) {
+        reload_app_window()
+      } else if(is_loading) {
         ui.calltree.clear_calltree()
         clear_coloring(ui)
         ui.render_debugger_loading(next)
diff --git a/src/index.js b/src/index.js
index 3984531..cd5d882 100644
--- a/src/index.js
+++ b/src/index.js
@@ -129,7 +129,7 @@ const init_app_window = w => {
           // If by that time w.closed was set to true, then page was
           // closed. Get back to using iframe
           globalThis.app_window = iframe.contentWindow
-          reload_app_window(get_state())
+          reload_app_window()
         } else {
           add_load_handler()
         }
@@ -140,7 +140,7 @@ const init_app_window = w => {
   add_load_handler()
 }
 
-const reload_app_window = state => {
+export const reload_app_window = (state = get_state()) => {
   // after window location reload, `run_code` command will be fired.
   globalThis.app_window.location = get_html_url(state)
 }
@@ -155,7 +155,7 @@ const get_entrypoint_settings = () => {
 
 export const exec_and_reload_app_window = (...exec_args) => {
   exec(...exec_args)
-  reload_app_window(get_state())
+  reload_app_window()
 }
 
 export const open_directory = () => {
diff --git a/src/runtime/runtime.js b/src/runtime/runtime.js
index aeaa7ec..a14508f 100644
--- a/src/runtime/runtime.js
+++ b/src/runtime/runtime.js
@@ -39,7 +39,16 @@ const make_promise_with_rejector = cxt => {
   return [p, rejector]
 }
 
-const do_run = function*(module_fns, cxt, io_trace){
+export const run = gen_to_promise(function*(module_fns, cxt, io_trace) {
+  if(!cxt.window.__is_initialized) {
+    defineMultiversion(cxt.window)
+    apply_io_patches(cxt.window)
+    inject_leporello_api(cxt)
+    cxt.window.__is_initialized = true
+  } else {
+    throw new Error('illegal state')
+  }
+
   let calltree
 
   const calltree_node_by_loc = new Map(
@@ -137,30 +146,6 @@ const do_run = function*(module_fns, cxt, io_trace){
     rt_cxt: cxt,
     calltree_node_by_loc,
   }
-}
-
-export const run = gen_to_promise(function*(module_fns, cxt, io_trace) {
-  if(!cxt.window.__is_initialized) {
-    defineMultiversion(cxt.window)
-    apply_io_patches(cxt.window)
-    inject_leporello_api(cxt)
-    cxt.window.__is_initialized = true
-  } else {
-    throw new Error('illegal state')
-  }
-
-  const result = yield* do_run(module_fns, cxt, io_trace)
-
-  if(result.rt_cxt.io_trace_is_replay_aborted) {
-    // TODO test next line
-    result.rt_cxt.is_recording_deferred_calls = false
-
-    // run again without io trace
-    // TODO reload app_window before second run
-    return yield* do_run(module_fns, cxt, null)
-  } else {
-    return result
-  }
 })
 
 const inject_leporello_api = cxt => {
diff --git a/test/utils.js b/test/utils.js
index 9364645..6e399f7 100644
--- a/test/utils.js
+++ b/test/utils.js
@@ -122,36 +122,48 @@ export const test_initial_state = (code, cursor_pos, options = {}) => {
   )
 }
 
-export const test_initial_state_async = async (code, ...args) => {
-  const s = test_initial_state(code, ...args)
-  assert_equal(s.eval_modules_state != null, true)
-  const result = await s.eval_modules_state.promise
+const wait_for_result = async state => {
+  assert_equal(state.eval_modules_state != null, true)
+  const result = await state.eval_modules_state.promise
   return COMMANDS.eval_modules_finished(
-    s, 
-    s,
+    state, 
+    state,
     result, 
   )
 }
 
+export const test_initial_state_async = async (code, ...args) => {
+  const s = test_initial_state(code, ...args)
+  return wait_for_result(s)
+}
+
 export const input = (s, code, index, options = {}) => {
   if(typeof(options) != 'object') {
     throw new Error('illegal state')
   }
   const {state, effects} = COMMANDS.input(s, code, index)
-  return {
-    state: run_code(state, options.app_window_patches),
-    effects,
+  const nextstate = run_code(state, options.app_window_patches)
+  if(nextstate.rt_cxt?.io_trace_is_replay_aborted) {
+    const with_clear_trace = run_code(
+      COMMANDS.clear_io_trace(nextstate), 
+      options.app_window_patches
+    )
+    return { state: with_clear_trace, effects }
+  } else {
+    return { state: nextstate, effects }
   }
 }
 
-export const input_async = async (...args) => {
-  const after_input = input(...args).state
-  const result = await after_input.eval_modules_state.promise
-  return COMMANDS.eval_modules_finished(
-    after_input, 
-    after_input,
-    result, 
-  )
+export const input_async = async (s, code, index, options) => {
+  const after_input = input(s, code, index, options).state
+  const state = await wait_for_result(after_input)
+  if(state.rt_cxt?.io_trace_is_replay_aborted) {
+    return wait_for_result(
+      run_code(COMMANDS.clear_io_trace(state), options.app_window_patches)
+    )
+  } else {
+    return state
+  }
 }
 
 export const test_deferred_calls_state = code => {