diff --git a/bazel/llvm.bzl b/bazel/llvm.bzl
index ce48adf5d..6da829f79 100644
--- a/bazel/llvm.bzl
+++ b/bazel/llvm.bzl
@@ -53,7 +53,7 @@ def _llvm_loader_repository(repository_ctx):
             executable = False,
         )
 
-LLVM_COMMIT_SHA = "5f1683ca1a4a582a73eabd79cad46a5294b35c33"
+LLVM_COMMIT_SHA = "d8474abfc1e7c3856b85b088f1133ae2e90da3d0"
 
 def llvm_loader_repository_dependencies():
     # This *declares* the dependency, but it won't actually be *downloaded* unless it's used.
diff --git a/cc_bindings_from_rs/generate_bindings/lib.rs b/cc_bindings_from_rs/generate_bindings/lib.rs
index 1a8812802..3ed59c8d4 100644
--- a/cc_bindings_from_rs/generate_bindings/lib.rs
+++ b/cc_bindings_from_rs/generate_bindings/lib.rs
@@ -1705,6 +1705,14 @@ fn generate_trait_impls<'a, 'tcx>(
                         if arg.flags().contains(has_type_or_const_vars()) {
                             return Err((impl_def_id, anyhow!("Implementation of traits must specify all types to receive bindings.")));
                         }
+                        if arg.walk().any(|arg| arg.as_type().is_some_and(|ty| ty.is_ptr_sized_integral())) {
+                            return Err((
+                                impl_def_id,
+                                anyhow!(
+                                    "b/491106325 - isize and usize types are not yet supported as trait type arguments."
+                                ),
+                            ));
+                        }
                         db.format_ty_for_cc(arg, TypeLocation::Other)
                             .map(|snippet| snippet.into_tokens(&mut prereqs))
                             .map_err(|err| (impl_def_id, err))