diff --git a/src/custom.rs b/src/custom.rs
index 22e44cc..76725bc 100644
--- a/src/custom.rs
+++ b/src/custom.rs
@@ -5,6 +5,7 @@ pub unsafe trait RefCastCustom<From: ?Sized> {
     fn __static_assert() {}
 }
 
+#[doc(hidden)]
 pub unsafe trait RefCastOkay<From>: Sealed<From> {
     type CurrentCrate;
     type Target: ?Sized;
@@ -28,6 +29,7 @@ where
     type Target = To;
 }
 
+#[doc(hidden)]
 pub trait Sealed<From> {}
 
 impl<'a, From, To> Sealed<&'a From> for &'a To
@@ -44,8 +46,10 @@ where
 {
 }
 
+#[doc(hidden)]
 pub type CurrentCrate<From, To> = <To as RefCastOkay<From>>::CurrentCrate;
 
+#[doc(hidden)]
 pub fn ref_cast_custom<From, To>(_arg: From)
 where
     To: RefCastOkay<From>,
diff --git a/src/layout.rs b/src/layout.rs
index 3f5e213..13f9196 100644
--- a/src/layout.rs
+++ b/src/layout.rs
@@ -1,7 +1,9 @@
 use core::{mem, usize};
 
+#[doc(hidden)]
 pub struct Layout<T: ?Sized>(T);
 
+#[doc(hidden)]
 pub trait LayoutUnsized<T: ?Sized> {
     const SIZE: usize = usize::MAX;
     const ALIGN: usize = usize::MAX;
@@ -14,6 +16,7 @@ impl<T> Layout<T> {
     pub const ALIGN: usize = mem::align_of::<T>();
 }
 
+#[doc(hidden)]
 #[inline]
 pub fn assert_layout<Outer: ?Sized, Inner: ?Sized>(
     name: &'static str,
diff --git a/src/lib.rs b/src/lib.rs
index bbc6a59..776801a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -182,8 +182,12 @@ pub trait RefCast {
 // Not public API.
 #[doc(hidden)]
 pub mod __private {
+    #[doc(hidden)]
     pub use crate::custom::{ref_cast_custom, CurrentCrate, RefCastCustom};
+    #[doc(hidden)]
     pub use crate::layout::{assert_layout, Layout, LayoutUnsized};
+    #[doc(hidden)]
     pub use crate::trivial::assert_trivial;
+    #[doc(hidden)]
     pub use core::mem::transmute;
 }
diff --git a/src/trivial.rs b/src/trivial.rs
index bcda772..b3e6d0d 100644
--- a/src/trivial.rs
+++ b/src/trivial.rs
@@ -2,6 +2,7 @@ use core::marker::PhantomData;
 #[cfg(not(no_phantom_pinned))]
 use core::marker::PhantomPinned;
 
+#[doc(hidden)]
 pub trait Trivial {}
 
 impl Trivial for () {}
@@ -10,4 +11,5 @@ impl<T: ?Sized> Trivial for PhantomData<T> {}
 #[cfg(not(no_phantom_pinned))]
 impl Trivial for PhantomPinned {}
 
+#[doc(hidden)]
 pub fn assert_trivial<T: Trivial>() {}