diff --git a/drivers/gpu/nova-core/gpu.rs b/drivers/gpu/nova-core/gpu.rs
index b3c91731db45..b603b0bd2692 100644
--- a/drivers/gpu/nova-core/gpu.rs
+++ b/drivers/gpu/nova-core/gpu.rs
@@ -285,10 +285,10 @@ pub(crate) struct Gpu<'gpu> {
 }
 
 impl<'gpu> Gpu<'gpu> {
-    pub(crate) fn new(
-        pdev: &'gpu pci::Device<device::Core<'_>>,
+    pub(crate) fn new<'a>(
+        pdev: &'gpu pci::Device<device::Core<'a>>,
         bar: Bar0<'gpu>,
-    ) -> impl PinInit<Self, Error> + 'gpu {
+    ) -> impl PinInit<Self, Error> + use<'gpu, 'a> {
         try_pin_init!(Self {
             device: pdev.as_ref(),
             spec: Spec::new(pdev.as_ref(), bar).inspect(|spec| {
diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
index b538c39982a6..82e46b37e814 100644
--- a/rust/kernel/device.rs
+++ b/rust/kernel/device.rs
@@ -504,7 +504,11 @@ pub trait DeviceContext: private::Sealed {}
 /// callback it appears in. It is intended to be used for synchronization purposes. Bus device
 /// implementations can implement methods for [`Device<Core>`], such that they can only be called
 /// from bus callbacks.
-pub struct Core<'a>(PhantomData<&'a ()>);
+///
+/// The lifetime `'a` is for "lifetime branding" purpose. Callbacks need to polymorphic over this
+/// lifetime so the `&'bound Device<Core<'_>>` provided to them cannot outlive the scope of the
+/// function. For this reason, it needs to be invariant.
+pub struct Core<'a>(PhantomData<fn(&'a ()) -> &'a ()>);
 
 /// Semantically the same as [`Core`], but reserved for internal usage of the corresponding bus
 /// abstraction.
@@ -515,7 +519,9 @@ pub trait DeviceContext: private::Sealed {}
 ///
 /// This context mainly exists to share generic [`Device`] infrastructure that should only be called
 /// from bus callbacks with bus abstractions, but without making them accessible for drivers.
-pub struct CoreInternal<'a>(PhantomData<&'a ()>);
+///
+/// Lifetime `'a` is invariant for the same reason as [`Core`].
+pub struct CoreInternal<'a>(PhantomData<fn(&'a ()) -> &'a ()>);
 
 /// Semantically the same as [`Bound`], but reserved for internal usage of the corresponding bus
 /// abstraction.
diff --git a/samples/rust/rust_debugfs.rs b/samples/rust/rust_debugfs.rs
index 1f59e08aaa4b..0b27ad96ecbf 100644
--- a/samples/rust/rust_debugfs.rs
+++ b/samples/rust/rust_debugfs.rs
@@ -147,7 +147,9 @@ fn build_inner(dir: &Dir) -> impl PinInit<File<Mutex<Inner>>> + '_ {
         dir.read_write_file(c"pair", new_mutex!(Inner { x: 3, y: 10 }))
     }
 
-    fn new<'a>(pdev: &'a platform::Device<Core<'_>>) -> impl PinInit<Self, Error> + 'a {
+    fn new<'a, 'b>(
+        pdev: &'a platform::Device<Core<'b>>,
+    ) -> impl PinInit<Self, Error> + use<'a, 'b> {
         let debugfs = Dir::new(c"sample_debugfs");
         let dev = pdev.as_ref();