diff --git a/libs/audio/source/combine/mixer.cpp b/libs/audio/source/combine/mixer.cpp
index 749f6fb3..520c1175 100644
--- a/libs/audio/source/combine/mixer.cpp
+++ b/libs/audio/source/combine/mixer.cpp
@@ -77,7 +77,8 @@ namespace psemek::audio
 
 				auto read = stream->read(buffer_);
 
-				std::copy(buffer_.data(), buffer_.data() + read, samples.begin());
+				for (auto src = buffer_.data(), dst = samples.begin(); src != buffer_.data() + read; ++src, ++dst)
+					*dst += *src;
 
 				if (read < buffer_.size())
 				{