diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1158f7f..0295254 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,8 @@
     I had at first thought that they'd assign registers and then inline, but it
     turns out that the inline phase happens way before the register assignment
     phase, so the macros were unnecessary (and clunky).
+  * **Break:** The `IrqFn` type is changed to pass the function an `IrqBits`
+    instead of a bare `u16`.
   * Adds a helper for using `stm` to set all controls of a DMA at once.
   * Adds functions to pick a screenblock location (one for each screenblock
     type).
diff --git a/src/interrupts.rs b/src/interrupts.rs
index fb3ea78..7de2f6e 100644
--- a/src/interrupts.rs
+++ b/src/interrupts.rs
@@ -1,7 +1,7 @@
 use crate::macros::{pub_const_fn_new_zeroed, u16_bool_field};
 
 /// A function you want called during an interrupt.
-pub type IrqFn = unsafe extern "C" fn(u16);
+pub type IrqFn = unsafe extern "C" fn(IrqBits);
 
 #[derive(Debug, Clone, Copy, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
 #[repr(transparent)]