diff --git a/embassy-nrf/src/buffered_uarte.rs b/embassy-nrf/src/buffered_uarte.rs
index 030fecf8..ceb52916 100644
--- a/embassy-nrf/src/buffered_uarte.rs
+++ b/embassy-nrf/src/buffered_uarte.rs
@@ -61,7 +61,7 @@ struct State<'a, U: Instance> {
 ///     - nrf52832: Section 15.2
 ///     - nrf52840: Section 6.1.2
 pub struct BufferedUarte<'a, U: Instance> {
-    inner: PeripheralMutex<U::Interrupt, State<'a, U>>,
+    inner: PeripheralMutex<State<'a, U>>,
 }
 
 impl<'a, U: Instance> Unpin for BufferedUarte<'a, U> {}
@@ -143,7 +143,6 @@ impl<'a, U: Instance> BufferedUarte<'a, U> {
 
         BufferedUarte {
             inner: PeripheralMutex::new(
-                irq,
                 State {
                     inner: uarte,
 
@@ -155,11 +154,12 @@ impl<'a, U: Instance> BufferedUarte<'a, U> {
                     tx_state: TxState::Idle,
                     tx_waker: WakerRegistration::new(),
                 },
+                irq,
             ),
         }
     }
 
-    fn inner(self: Pin<&mut Self>) -> Pin<&mut PeripheralMutex<U::Interrupt, State<'a, U>>> {
+    fn inner(self: Pin<&mut Self>) -> Pin<&mut PeripheralMutex<State<'a, U>>> {
         unsafe { Pin::new_unchecked(&mut self.get_unchecked_mut().inner) }
     }
 }
@@ -173,7 +173,7 @@ impl<'a, U: Instance> Drop for BufferedUarte<'a, U> {
 
 impl<'a, U: Instance> AsyncBufRead for BufferedUarte<'a, U> {
     fn poll_fill_buf(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<&[u8]>> {
-        self.inner().with(|_irq, state| {
+        self.inner().with(|state, _irq| {
             // Conservative compiler fence to prevent optimizations that do not
             // take in to account actions by DMA. The fence has been placed here,
             // before any DMA action has started
@@ -203,7 +203,7 @@ impl<'a, U: Instance> AsyncBufRead for BufferedUarte<'a, U> {
     }
 
     fn consume(self: Pin<&mut Self>, amt: usize) {
-        self.inner().with(|irq, state| {
+        self.inner().with(|state, irq| {
             trace!("consume {:?}", amt);
             state.rx.pop(amt);
             irq.pend();
@@ -213,7 +213,7 @@ impl<'a, U: Instance> AsyncBufRead for BufferedUarte<'a, U> {
 
 impl<'a, U: Instance> AsyncWrite for BufferedUarte<'a, U> {
     fn poll_write(self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8]) -> Poll<Result<usize>> {
-        self.inner().with(|irq, state| {
+        self.inner().with(|state, irq| {
             trace!("poll_write: {:?}", buf.len());
 
             let tx_buf = state.tx.push_buf();
@@ -242,6 +242,8 @@ impl<'a, U: Instance> AsyncWrite for BufferedUarte<'a, U> {
 }
 
 impl<'a, U: Instance> PeripheralState for State<'a, U> {
+    type Interrupt = U::Interrupt;
+
     fn on_interrupt(&mut self) {
         trace!("irq: start");
         let mut more_work = true;
diff --git a/embassy-nrf/src/util/peripheral.rs b/embassy-nrf/src/util/peripheral.rs
index 07dc4a7b..e0edbf2b 100644
--- a/embassy-nrf/src/util/peripheral.rs
+++ b/embassy-nrf/src/util/peripheral.rs
@@ -6,25 +6,26 @@ use crate::fmt::*;
 use crate::interrupt::OwnedInterrupt;
 
 pub trait PeripheralState {
+    type Interrupt: OwnedInterrupt;
     fn on_interrupt(&mut self);
 }
 
-pub struct PeripheralMutex<I: OwnedInterrupt, S: PeripheralState> {
-    inner: Option<(I, UnsafeCell<S>)>,
+pub struct PeripheralMutex<S: PeripheralState> {
+    inner: Option<(UnsafeCell<S>, S::Interrupt)>,
     not_send: PhantomData<*mut ()>,
 }
 
-impl<I: OwnedInterrupt, S: PeripheralState> PeripheralMutex<I, S> {
-    pub fn new(irq: I, state: S) -> Self {
+impl<S: PeripheralState> PeripheralMutex<S> {
+    pub fn new(state: S, irq: S::Interrupt) -> Self {
         Self {
-            inner: Some((irq, UnsafeCell::new(state))),
+            inner: Some((UnsafeCell::new(state), irq)),
             not_send: PhantomData,
         }
     }
 
-    pub fn with<R>(self: Pin<&mut Self>, f: impl FnOnce(&mut I, &mut S) -> R) -> R {
+    pub fn with<R>(self: Pin<&mut Self>, f: impl FnOnce(&mut S, &mut S::Interrupt) -> R) -> R {
         let this = unsafe { self.get_unchecked_mut() };
-        let (irq, state) = unwrap!(this.inner.as_mut());
+        let (state, irq) = unwrap!(this.inner.as_mut());
 
         irq.disable();
         compiler_fence(Ordering::SeqCst);
@@ -43,7 +44,7 @@ impl<I: OwnedInterrupt, S: PeripheralState> PeripheralMutex<I, S> {
         // Safety: it's OK to get a &mut to the state, since the irq is disabled.
         let state = unsafe { &mut *state.get() };
 
-        let r = f(irq, state);
+        let r = f(state, irq);
 
         compiler_fence(Ordering::SeqCst);
         irq.enable();
@@ -51,18 +52,18 @@ impl<I: OwnedInterrupt, S: PeripheralState> PeripheralMutex<I, S> {
         r
     }
 
-    pub fn free(self: Pin<&mut Self>) -> (I, S) {
+    pub fn free(self: Pin<&mut Self>) -> (S, S::Interrupt) {
         let this = unsafe { self.get_unchecked_mut() };
-        let (irq, state) = unwrap!(this.inner.take());
+        let (state, irq) = unwrap!(this.inner.take());
         irq.disable();
         irq.remove_handler();
-        (irq, state.into_inner())
+        (state.into_inner(), irq)
     }
 }
 
-impl<I: OwnedInterrupt, S: PeripheralState> Drop for PeripheralMutex<I, S> {
+impl<S: PeripheralState> Drop for PeripheralMutex<S> {
     fn drop(&mut self) {
-        if let Some((irq, state)) = &mut self.inner {
+        if let Some((state, irq)) = &mut self.inner {
             irq.disable();
             irq.remove_handler();
         }