diff --git a/src/audio_history.rs b/src/audio_history.rs
index ef928fd..9d3da3b 100644
--- a/src/audio_history.rs
+++ b/src/audio_history.rs
@@ -323,7 +323,6 @@ mod tests {
 
         hist.update([0.0].repeat(hist.data().capacity() * 2).iter().copied());
 
-        let sample = hist.index_to_sample_info(0);
         assert_eq!(
             hist.index_to_sample_info(0).duration_behind,
             Duration::from_secs_f32((DEFAULT_BUFFER_SIZE - 1) as f32)
diff --git a/src/beat_detector.rs b/src/beat_detector.rs
index 7d28449..865697e 100644
--- a/src/beat_detector.rs
+++ b/src/beat_detector.rs
@@ -1,6 +1,6 @@
 use crate::EnvelopeInfo;
 use crate::{AudioHistory, EnvelopeIterator};
-use biquad::{coefficients, Biquad, Coefficients, DirectForm1, ToHertz, Type, Q_BUTTERWORTH_F32};
+use biquad::{Biquad, Coefficients, DirectForm1, ToHertz, Type, Q_BUTTERWORTH_F32};
 use std::fmt::{Debug, Formatter};
 
 /// Cutoff frequency for the lowpass filter to detect beats.
@@ -102,7 +102,7 @@ mod tests {
 
     #[test]
     fn is_send_and_sync() {
-        fn accept<I: Send + Sync>() {};
+        fn accept<I: Send + Sync>() {}
 
         accept::<BeatDetector>();
     }
diff --git a/src/envelope_iterator.rs b/src/envelope_iterator.rs
index 338a30c..da0adf5 100644
--- a/src/envelope_iterator.rs
+++ b/src/envelope_iterator.rs
@@ -1,5 +1,5 @@
+use crate::MaxMinIterator;
 use crate::{AudioHistory, SampleInfo};
-use crate::{AudioInput, MaxMinIterator};
 use core::cmp::Ordering;
 use core::time::Duration;
 use ringbuffer::RingBuffer;