diff --git a/Cargo.toml b/Cargo.toml
index acf993ae2..3bc731c60 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -56,11 +56,7 @@ device-selected = []
 direct-call-deprecated = []
 rt = ["stm32f3/rt"]
 # Any Changes here should be mirrored in README.md and src/lib.rs
-stm32f301 = ["stm32f3/stm32f301", "direct-call-deprecated"]
-stm32f301xb = ["stm32f301", "device-selected"]
-stm32f301xc = ["stm32f301", "device-selected"]
-stm32f301xd = ["stm32f301", "device-selected"]
-stm32f301xe = ["stm32f301", "device-selected"]
+stm32f301 = ["stm32f3/stm32f301", "device-selected"]
 stm32f318 = ["stm32f3/stm32f3x8", "device-selected"]
 stm32f302 = ["stm32f3/stm32f302", "direct-call-deprecated"]
 stm32f302xb = ["stm32f302", "device-selected"]
diff --git a/src/lib.rs b/src/lib.rs
index edd67042a..d6f7cdf55 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -6,10 +6,7 @@
    Please select one of the following
 
    (Note: `x` denotes any character in [a-z])
-   *   stm32f301xb
-   *   stm32f301xc
-   *   stm32f301xd
-   *   stm32f301xe
+   *   stm32f301
    *   stm32f318
    *   stm32f302xb
    *   stm32f302xc
@@ -43,10 +40,7 @@ compile_error!(
     Please select one of the following
 
     (Note: `x` denotes any character in [a-z])
-    *   stm32f301xb
-    *   stm32f301xc
-    *   stm32f301xd
-    *   stm32f301xe
+    *   stm32f301
     *   stm32f318
     *   stm32f302xb
     *   stm32f302xc
diff --git a/src/serial.rs b/src/serial.rs
index e419ff821..321cc93b9 100644
--- a/src/serial.rs
+++ b/src/serial.rs
@@ -8,8 +8,6 @@ use crate::{
     time::Bps,
 };
 use core::{convert::Infallible, marker::PhantomData, ptr};
-use cortex_m::interrupt;
-use nb;
 
 #[cfg(any(
     feature = "stm32f302",
@@ -41,6 +39,8 @@ use crate::gpio::gpioe;
 
 #[cfg(feature = "stm32f303")]
 use crate::dma;
+#[cfg(feature = "stm32f303")]
+use cortex_m::interrupt;
 
 /// Interrupt event
 pub enum Event {
diff --git a/src/spi.rs b/src/spi.rs
index 7788684f0..18d5ba252 100644
--- a/src/spi.rs
+++ b/src/spi.rs
@@ -5,7 +5,6 @@ use core::ptr;
 use crate::hal::spi::FullDuplex;
 pub use crate::hal::spi::{Mode, Phase, Polarity};
 use crate::pac::{SPI1, SPI2, SPI3};
-use nb;
 
 use crate::gpio::gpioa::{PA5, PA6, PA7};
 #[cfg(any(
diff --git a/src/timer.rs b/src/timer.rs
index 37d7d81ed..eb7d9c067 100644
--- a/src/timer.rs
+++ b/src/timer.rs
@@ -56,7 +56,6 @@ use crate::pac::{TIM15, TIM16, TIM17, TIM2, TIM6};
 use crate::pac::{TIM3, TIM7};
 
 use cast::{u16, u32};
-use nb;
 use void::Void;
 
 use crate::rcc::{Clocks, APB1, APB2};