diff --git a/src/iir.rs b/src/iir.rs
index 6d02e17..d3a60e8 100644
--- a/src/iir.rs
+++ b/src/iir.rs
@@ -23,7 +23,7 @@ fn copysign(x: f32, y: f32) -> f32 {
 }
 
 fn macc(y0: f32, x: &[f32], a: &[f32]) -> f32 {
-    y0 + x.iter().zip(a.iter()) .map(|(&i, &j)| i * j).sum::<f32>()
+    y0 + x.iter().zip(a.iter()).map(|(&i, &j)| i * j).sum::<f32>()
 }
 
 impl IIR {
diff --git a/src/main.rs b/src/main.rs
index 83d7c4b..1eb6556 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,17 +3,12 @@
 #![feature(asm)]
 // Enable returning `!`
 #![feature(never_type)]
-#[allow(unused_extern_crates)]
 
 #[cfg(not(feature = "semihosting"))]
 extern crate panic_abort;
 #[cfg(feature = "semihosting")]
 extern crate panic_semihosting;
 
-extern crate cortex_m;
-extern crate cortex_m_rt;
-extern crate stm32h7;
-
 #[macro_use]
 extern crate log;