diff --git a/modules/audio_device/ios/audio_device_ios.h b/modules/audio_device/ios/audio_device_ios.h
index c51a9799da5..b1d40537af5 100644
--- a/modules/audio_device/ios/audio_device_ios.h
+++ b/modules/audio_device/ios/audio_device_ios.h
@@ -195,6 +195,9 @@ class AudioDeviceIOS : public AudioDeviceGeneric,
   // Closes and deletes the voice-processing I/O unit.
   void ShutdownPlayOrRecord();
 
+  // Resets thread-checkers before a call is restarted.
+  void PrepareForNewStart();
+
   // Ensures that methods are called from the same thread as this object is
   // created on.
   rtc::ThreadChecker thread_checker_;
diff --git a/modules/audio_device/ios/audio_device_ios.mm b/modules/audio_device/ios/audio_device_ios.mm
index 36da53819fa..f8aae2efe6d 100644
--- a/modules/audio_device/ios/audio_device_ios.mm
+++ b/modules/audio_device/ios/audio_device_ios.mm
@@ -491,15 +491,7 @@ static void LogDeviceInfo() {
     if (!audio_unit_->Stop()) {
       RTCLogError(@"Failed to stop the audio unit for interruption begin.");
     } else {
-      // The audio unit has been stopped but will be restarted when the
-      // interruption ends in HandleInterruptionEnd(). It will result in audio
-      // callbacks from a new native I/O thread which means that we must detach
-      // thread checkers here to be prepared for an upcoming new audio stream.
-      io_thread_checker_.DetachFromThread();
-      // The audio device buffer must also be informed about the interrupted
-      // state so it can detach its thread checkers as well.
-      audio_device_buffer_->NativeAudioPlayoutInterrupted();
-      audio_device_buffer_->NativeAudioRecordingInterrupted();
+      PrepareForNewStart();
     }
   }
   is_interrupted_ = true;
@@ -581,6 +573,7 @@ static void LogDeviceInfo() {
   if (audio_unit_->GetState() == VoiceProcessingAudioUnit::kStarted) {
     audio_unit_->Stop();
     restart_audio_unit = true;
+    PrepareForNewStart();
   }
   if (audio_unit_->GetState() == VoiceProcessingAudioUnit::kInitialized) {
     audio_unit_->Uninitialize();
@@ -901,4 +894,19 @@ static void LogDeviceInfo() {
   [session unlockForConfiguration];
 }
 
+void AudioDeviceIOS::PrepareForNewStart() {
+  LOGI() << "PrepareForNewStart";
+  // The audio unit has been stopped and preparations are needed for an upcoming
+  // restart. It will result in audio callbacks from a new native I/O thread
+  // which means that we must detach thread checkers here to be prepared for an
+  // upcoming new audio stream.
+  io_thread_checker_.DetachFromThread();
+  // The audio device buffer must also be informed about the interrupted
+  // state so it can detach its thread checkers as well.
+  if (audio_device_buffer_) {
+    audio_device_buffer_->NativeAudioPlayoutInterrupted();
+    audio_device_buffer_->NativeAudioRecordingInterrupted();
+  }
+}
+
 }  // namespace webrtc
diff --git a/sdk/objc/Framework/Native/src/audio/audio_device_ios.h b/sdk/objc/Framework/Native/src/audio/audio_device_ios.h
index 250826de188..4001f49055e 100644
--- a/sdk/objc/Framework/Native/src/audio/audio_device_ios.h
+++ b/sdk/objc/Framework/Native/src/audio/audio_device_ios.h
@@ -198,6 +198,9 @@ class AudioDeviceIOS : public AudioDeviceGeneric,
   // Closes and deletes the voice-processing I/O unit.
   void ShutdownPlayOrRecord();
 
+  // Resets thread-checkers before a call is restarted.
+  void PrepareForNewStart();
+
   // Ensures that methods are called from the same thread as this object is
   // created on.
   rtc::ThreadChecker thread_checker_;
diff --git a/sdk/objc/Framework/Native/src/audio/audio_device_ios.mm b/sdk/objc/Framework/Native/src/audio/audio_device_ios.mm
index cf254869c09..3779c2552e4 100644
--- a/sdk/objc/Framework/Native/src/audio/audio_device_ios.mm
+++ b/sdk/objc/Framework/Native/src/audio/audio_device_ios.mm
@@ -497,15 +497,7 @@ static void LogDeviceInfo() {
     if (!audio_unit_->Stop()) {
       RTCLogError(@"Failed to stop the audio unit for interruption begin.");
     } else {
-      // The audio unit has been stopped but will be restarted when the
-      // interruption ends in HandleInterruptionEnd(). It will result in audio
-      // callbacks from a new native I/O thread which means that we must detach
-      // thread checkers here to be prepared for an upcoming new audio stream.
-      io_thread_checker_.DetachFromThread();
-      // The audio device buffer must also be informed about the interrupted
-      // state so it can detach its thread checkers as well.
-      audio_device_buffer_->NativeAudioPlayoutInterrupted();
-      audio_device_buffer_->NativeAudioRecordingInterrupted();
+      PrepareForNewStart();
     }
   }
   is_interrupted_ = true;
@@ -587,6 +579,7 @@ static void LogDeviceInfo() {
   if (audio_unit_->GetState() == VoiceProcessingAudioUnit::kStarted) {
     audio_unit_->Stop();
     restart_audio_unit = true;
+    PrepareForNewStart();
   }
   if (audio_unit_->GetState() == VoiceProcessingAudioUnit::kInitialized) {
     audio_unit_->Uninitialize();
@@ -907,6 +900,21 @@ static void LogDeviceInfo() {
   [session unlockForConfiguration];
 }
 
+void AudioDeviceIOS::PrepareForNewStart() {
+  LOGI() << "PrepareForNewStart";
+  // The audio unit has been stopped and preparations are needed for an upcoming
+  // restart. It will result in audio callbacks from a new native I/O thread
+  // which means that we must detach thread checkers here to be prepared for an
+  // upcoming new audio stream.
+  io_thread_checker_.DetachFromThread();
+  // The audio device buffer must also be informed about the interrupted
+  // state so it can detach its thread checkers as well.
+  if (audio_device_buffer_) {
+    audio_device_buffer_->NativeAudioPlayoutInterrupted();
+    audio_device_buffer_->NativeAudioRecordingInterrupted();
+  }
+}
+
 bool AudioDeviceIOS::IsInterrupted() {
   return is_interrupted_;
 }