diff --git a/repos/os/include/audio_out_session/audio_out_session.h b/repos/os/include/audio_out_session/audio_out_session.h
index 18d651ad4..f3b81c124 100644
--- a/repos/os/include/audio_out_session/audio_out_session.h
+++ b/repos/os/include/audio_out_session/audio_out_session.h
@@ -94,7 +94,7 @@ class Audio_out::Packet
 			Genode::memcpy(_data, data, (samples > PERIOD ? PERIOD : samples) * SAMPLE_SIZE);
 
 			if (samples < PERIOD)
-				Genode::memset(data + samples, 0, (PERIOD - samples) * SAMPLE_SIZE);
+				Genode::memset(_data + samples, 0, (PERIOD - samples) * SAMPLE_SIZE);
 		}
 
 		/**