diff --git a/crates/bevy_render/src/lib.rs b/crates/bevy_render/src/lib.rs
index f595023588e768..5f3e4140687588 100644
--- a/crates/bevy_render/src/lib.rs
+++ b/crates/bevy_render/src/lib.rs
@@ -1,3 +1,6 @@
+#[cfg(target_pointer_width = "16")]
+compile_error!("bevy_render cannot compile for a 16-bit platform.");
+
 extern crate core;
 
 pub mod camera;
diff --git a/crates/bevy_render/src/render_phase/draw.rs b/crates/bevy_render/src/render_phase/draw.rs
index 67ff987b7972d4..14930b1931ffa2 100644
--- a/crates/bevy_render/src/render_phase/draw.rs
+++ b/crates/bevy_render/src/render_phase/draw.rs
@@ -65,7 +65,7 @@ pub trait PhaseItem: Sized + Send + Sync + 'static {
 // TODO: make this generic?
 /// An identifier for a [`Draw`] function stored in [`DrawFunctions`].
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
-pub struct DrawFunctionId(usize);
+pub struct DrawFunctionId(u32);
 
 /// Stores all draw functions for the [`PhaseItem`] type.
 /// For retrieval they are associated with their [`TypeId`].
@@ -82,15 +82,15 @@ impl<P: PhaseItem> DrawFunctionsInternal<P> {
 
     /// Adds the [`Draw`] function and associates it to the type `T`
     pub fn add_with<T: 'static, D: Draw<P>>(&mut self, draw_function: D) -> DrawFunctionId {
+        let id = DrawFunctionId(self.draw_functions.len().try_into().unwrap());
         self.draw_functions.push(Box::new(draw_function));
-        let id = DrawFunctionId(self.draw_functions.len() - 1);
         self.indices.insert(TypeId::of::<T>(), id);
         id
     }
 
     /// Retrieves the [`Draw`] function corresponding to the `id` mutably.
     pub fn get_mut(&mut self, id: DrawFunctionId) -> Option<&mut dyn Draw<P>> {
-        self.draw_functions.get_mut(id.0).map(|f| &mut **f)
+        self.draw_functions.get_mut(id.0 as usize).map(|f| &mut **f)
     }
 
     /// Retrieves the id of the [`Draw`] function corresponding to their associated type `T`.