diff --git a/agb/src/sound/mixer/sw_mixer.rs b/agb/src/sound/mixer/sw_mixer.rs
index ffa637f3..a147fd21 100644
--- a/agb/src/sound/mixer/sw_mixer.rs
+++ b/agb/src/sound/mixer/sw_mixer.rs
@@ -422,11 +422,7 @@ impl MixerBuffer {
     ) {
         working_buffer.fill(0.into());
 
-        for channel in channels {
-            if channel.is_done {
-                continue;
-            }
-
+        for channel in channels.filter(|channel| !channel.is_done) {
             let playback_speed = if channel.is_stereo {
                 2.into()
             } else {