diff --git a/sys/dev/audio/audio.c b/sys/dev/audio/audio.c
index 176749ac449f..519cc098d03a 100644
--- a/sys/dev/audio/audio.c
+++ b/sys/dev/audio/audio.c
@@ -5879,8 +5879,7 @@ audio_rmixer_process(struct audio_softc *sc)
 		/* If the track buffer is full, discard the oldest one? */
 		input = track->input;
 		if (input->capacity - input->used < mixer->frames_per_block) {
-			int drops = mixer->frames_per_block -
-			    (input->capacity - input->used);
+			int drops = mixer->frames_per_block;
 			track->dropframes += drops;
 			TRACET(4, track, "drop %d frames: inp=%d/%d/%d",
 			    drops,