diff --git a/examples/audio.cpp b/examples/audio.cpp
index 3a821a1f..8370efc1 100644
--- a/examples/audio.cpp
+++ b/examples/audio.cpp
@@ -68,7 +68,7 @@ struct audio_app
 		left_volume_ = audio::volume(dup1, 0.5f, 0.1f);
 		right_volume_ = audio::volume(dup2, 0.5f, 0.1f);
 		auto result = audio::stereo(left_volume_, right_volume_);
-		engine_.output(result);
+		engine_.output()->stream(result);
 	}
 
 	void on_key_down(SDL_Keycode key) override
@@ -90,7 +90,8 @@ struct audio_app
 		if (channels_.contains(key))
 		{
 			auto & ch = channels_[key];
-			ch->stream(audio::fade_out(ch->stream(), 0.01f));
+			if (auto s = ch->stream())
+				ch->stream(audio::fade_out(s, 0.01f));
 			channels_.erase(key);
 		}
 	}
diff --git a/libs/audio/include/psemek/audio/channel.hpp b/libs/audio/include/psemek/audio/channel.hpp
index 83d43606..3df9cfef 100644
--- a/libs/audio/include/psemek/audio/channel.hpp
+++ b/libs/audio/include/psemek/audio/channel.hpp
@@ -10,6 +10,8 @@ namespace psemek::audio
 
 	struct channel
 	{
+		channel() = default;
+
 		channel(stream_ptr stream)
 			: stream_(std::move(stream))
 		{}
diff --git a/libs/audio/include/psemek/audio/engine.hpp b/libs/audio/include/psemek/audio/engine.hpp
index ab51e87b..2731262f 100644
--- a/libs/audio/include/psemek/audio/engine.hpp
+++ b/libs/audio/include/psemek/audio/engine.hpp
@@ -2,6 +2,7 @@
 
 #include <psemek/audio/stream.hpp>
 #include <psemek/audio/track.hpp>
+#include <psemek/audio/channel.hpp>
 
 #include <psemek/util/pimpl.hpp>
 #include <psemek/util/span.hpp>
@@ -21,7 +22,7 @@ namespace psemek::audio
 		track_ptr load(float const * data, std::size_t sample_count, bool copy = true);
 		track_ptr load(util::span<float> data, bool copy = true);
 
-		stream_ptr output(stream_ptr stream);
+		channel_ptr output();
 
 	private:
 		psemek_declare_pimpl
diff --git a/libs/audio/source/engine.cpp b/libs/audio/source/engine.cpp
index 8aeba41d..251f62b9 100644
--- a/libs/audio/source/engine.cpp
+++ b/libs/audio/source/engine.cpp
@@ -23,7 +23,7 @@ namespace psemek::audio
 		std::vector<float> buffer;
 		bool thread_registered = false;
 
-		stream_ptr output;
+		channel_ptr output;
 
 		impl();
 		~impl();
@@ -49,6 +49,8 @@ namespace psemek::audio
 		SDL_PauseAudioDevice(device, 0);
 
 		log::info() << "Initialized audio: " << static_cast<int>(obtained.channels) << " channels, " << obtained.freq << " Hz, " << obtained.samples << " samples";
+
+		output = std::make_shared<channel>();
 	}
 
 	engine::impl::~impl()
@@ -59,7 +61,7 @@ namespace psemek::audio
 	void engine::impl::callback(void * userdata, std::uint8_t * dst_u8, int len)
 	{
 		auto self = static_cast<impl *>(userdata);
-		stream_ptr output = std::atomic_load(&(self->output));
+		stream_ptr output = self->output->stream();
 		std::int16_t * dst = reinterpret_cast<std::int16_t *>(dst_u8);
 
 		if (!self->thread_registered)
@@ -101,9 +103,9 @@ namespace psemek::audio
 		return load(data.data(), data.size(), copy);
 	}
 
-	stream_ptr engine::output(stream_ptr stream)
+	channel_ptr engine::output()
 	{
-		return std::atomic_exchange(&(impl().output), std::move(stream));
+		return impl().output;
 	}
 
 }