diff --git a/crates/rustc_codegen_spirv/src/codegen_cx/entry.rs b/crates/rustc_codegen_spirv/src/codegen_cx/entry.rs
index aff4152435..7acca2a39b 100644
--- a/crates/rustc_codegen_spirv/src/codegen_cx/entry.rs
+++ b/crates/rustc_codegen_spirv/src/codegen_cx/entry.rs
@@ -9,7 +9,7 @@ use crate::builder_spirv::{SpirvFunctionCursor, SpirvValue, SpirvValueExt};
 use crate::spirv_type::SpirvType;
 use rspirv::dr::Operand;
 use rspirv::spirv::{
-    Capability, Decoration, Dim, ExecutionModel, FunctionControl, StorageClass, Word,
+    BuiltIn, Capability, Decoration, Dim, ExecutionModel, FunctionControl, StorageClass, Word,
 };
 use rustc_abi::FieldsShape;
 use rustc_codegen_ssa::traits::{BaseTypeCodegenMethods, BuilderMethods, MiscCodegenMethods as _};
@@ -916,6 +916,11 @@ impl<'tcx> CodegenCx<'tcx> {
             );
         }
 
+        // Check builtin-specific type requirements.
+        if let Some(builtin) = attrs.builtin {
+            self.check_builtin_type(hir_param.ty_span, value_layout.ty, builtin);
+        }
+
         if let Ok(storage_class) = storage_class {
             self.check_for_bad_types(
                 execution_model,
@@ -1083,4 +1088,15 @@ impl<'tcx> CodegenCx<'tcx> {
             }
         }
     }
+
+    /// Check that builtin variables have the correct type.
+    fn check_builtin_type(&self, span: Span, rust_ty: Ty<'tcx>, builtin: Spanned<BuiltIn>) {
+        // LocalInvocationIndex must be a u32.
+        if builtin.value == BuiltIn::LocalInvocationIndex && rust_ty != self.tcx.types.u32 {
+            self.tcx.dcx().span_err(
+                span,
+                format!("`#[spirv(local_invocation_index)]` must be a `u32`, not `{rust_ty}`"),
+            );
+        }
+    }
 }
diff --git a/tests/compiletests/ui/arch/shared/dce_shared.rs b/tests/compiletests/ui/arch/shared/dce_shared.rs
index 2c639ae5fc..f06aa6bbcc 100644
--- a/tests/compiletests/ui/arch/shared/dce_shared.rs
+++ b/tests/compiletests/ui/arch/shared/dce_shared.rs
@@ -21,10 +21,10 @@ pub fn main(
     #[spirv(descriptor_set = 0, binding = 1, storage_buffer)] output: &mut f32,
     #[spirv(workgroup)] used_shared: &mut f32,
     #[spirv(workgroup)] dce_shared: &mut [i32; 2],
-    #[spirv(local_invocation_index)] inv_id: UVec3,
+    #[spirv(local_invocation_index)] inv_id: u32,
 ) {
     unsafe {
-        let inv_id = inv_id.x as usize;
+        let inv_id = inv_id as usize;
         if inv_id == 0 {
             *used_shared = *input;
         }
diff --git a/tests/compiletests/ui/arch/shared/dce_shared.stderr b/tests/compiletests/ui/arch/shared/dce_shared.stderr
index 532063d2ac..681d038026 100644
--- a/tests/compiletests/ui/arch/shared/dce_shared.stderr
+++ b/tests/compiletests/ui/arch/shared/dce_shared.stderr
@@ -20,16 +20,15 @@ OpDecorate %4 BuiltIn LocalInvocationIndex
 %11 = OpTypePointer Workgroup %9
 %12 = OpTypeInt 32 0
 %13 = OpConstant  %12  2
-%14 = OpTypeVector %12 3
-%15 = OpTypePointer Input %14
-%16 = OpTypeVoid
-%17 = OpTypeFunction %16
-%18 = OpTypePointer StorageBuffer %9
+%14 = OpTypePointer Input %12
+%15 = OpTypeVoid
+%16 = OpTypeFunction %15
+%17 = OpTypePointer StorageBuffer %9
 %2 = OpVariable  %10  StorageBuffer
-%19 = OpConstant  %12  0
+%18 = OpConstant  %12  0
 %3 = OpVariable  %10  StorageBuffer
-%4 = OpVariable  %15  Input
-%20 = OpTypeBool
+%4 = OpVariable  %14  Input
+%19 = OpTypeBool
 %5 = OpVariable  %11  Workgroup
-%21 = OpConstant  %12  264
-%22 = OpConstant  %12  1
+%20 = OpConstant  %12  264
+%21 = OpConstant  %12  1
diff --git a/tests/compiletests/ui/arch/shared/reduction_array.rs b/tests/compiletests/ui/arch/shared/reduction_array.rs
index 5ccd4136c5..a9a4238abb 100644
--- a/tests/compiletests/ui/arch/shared/reduction_array.rs
+++ b/tests/compiletests/ui/arch/shared/reduction_array.rs
@@ -57,10 +57,10 @@ pub fn main(
     #[spirv(descriptor_set = 0, binding = 0, storage_buffer)] input: &[Value],
     #[spirv(descriptor_set = 0, binding = 1, storage_buffer)] output: &mut Value,
     #[spirv(workgroup)] shared: &mut [Value; WG_SIZE],
-    #[spirv(local_invocation_index)] inv_id: UVec3,
+    #[spirv(local_invocation_index)] inv_id: u32,
 ) {
     unsafe {
-        let inv_id = inv_id.x as usize;
+        let inv_id = inv_id as usize;
         shared[inv_id] = input[inv_id];
         workgroup_memory_barrier_with_group_sync();
 
diff --git a/tests/compiletests/ui/arch/shared/reduction_big_struct.rs b/tests/compiletests/ui/arch/shared/reduction_big_struct.rs
index 809508ca68..5e651cfb9d 100644
--- a/tests/compiletests/ui/arch/shared/reduction_big_struct.rs
+++ b/tests/compiletests/ui/arch/shared/reduction_big_struct.rs
@@ -65,10 +65,10 @@ pub fn main(
     #[spirv(descriptor_set = 0, binding = 0, storage_buffer)] input: &[Value],
     #[spirv(descriptor_set = 0, binding = 1, storage_buffer)] output: &mut Value,
     #[spirv(workgroup)] shared: &mut [Value; WG_SIZE],
-    #[spirv(local_invocation_index)] inv_id: UVec3,
+    #[spirv(local_invocation_index)] inv_id: u32,
 ) {
     unsafe {
-        let inv_id = inv_id.x as usize;
+        let inv_id = inv_id as usize;
         shared[inv_id] = input[inv_id];
         workgroup_memory_barrier_with_group_sync();
 
diff --git a/tests/compiletests/ui/arch/shared/reduction_u32.rs b/tests/compiletests/ui/arch/shared/reduction_u32.rs
index 0f60e495df..7e114bb093 100644
--- a/tests/compiletests/ui/arch/shared/reduction_u32.rs
+++ b/tests/compiletests/ui/arch/shared/reduction_u32.rs
@@ -22,10 +22,10 @@ pub fn main(
     #[spirv(descriptor_set = 0, binding = 0, storage_buffer)] input: &[Value],
     #[spirv(descriptor_set = 0, binding = 1, storage_buffer)] output: &mut Value,
     #[spirv(workgroup)] shared: &mut [Value; WG_SIZE],
-    #[spirv(local_invocation_index)] inv_id: UVec3,
+    #[spirv(local_invocation_index)] inv_id: u32,
 ) {
     unsafe {
-        let inv_id = inv_id.x as usize;
+        let inv_id = inv_id as usize;
         shared[inv_id] = input[inv_id];
         workgroup_memory_barrier_with_group_sync();
 
diff --git a/tests/compiletests/ui/arch/shared/reduction_vec.rs b/tests/compiletests/ui/arch/shared/reduction_vec.rs
index 7fe18d1af3..10f851268d 100644
--- a/tests/compiletests/ui/arch/shared/reduction_vec.rs
+++ b/tests/compiletests/ui/arch/shared/reduction_vec.rs
@@ -22,10 +22,10 @@ pub fn main(
     #[spirv(descriptor_set = 0, binding = 0, storage_buffer)] input: &[Value],
     #[spirv(descriptor_set = 0, binding = 1, storage_buffer)] output: &mut Value,
     #[spirv(workgroup)] shared: &mut [Value; WG_SIZE],
-    #[spirv(local_invocation_index)] inv_id: UVec3,
+    #[spirv(local_invocation_index)] inv_id: u32,
 ) {
     unsafe {
-        let inv_id = inv_id.x as usize;
+        let inv_id = inv_id as usize;
         shared[inv_id] = input[inv_id];
         workgroup_memory_barrier_with_group_sync();
 
diff --git a/tests/compiletests/ui/arch/subgroup/subgroup_composite.rs b/tests/compiletests/ui/arch/subgroup/subgroup_composite.rs
index 5db5ba963e..9dd1ae0827 100644
--- a/tests/compiletests/ui/arch/subgroup/subgroup_composite.rs
+++ b/tests/compiletests/ui/arch/subgroup/subgroup_composite.rs
@@ -30,7 +30,7 @@ pub struct Zst;
 
 #[spirv(compute(threads(32)))]
 pub fn main(
-    #[spirv(local_invocation_index)] inv_id: UVec3,
+    #[spirv(local_invocation_id)] inv_id: UVec3,
     #[spirv(descriptor_set = 0, binding = 0, storage_buffer)] output: &mut UVec3,
 ) {
     unsafe {
diff --git a/tests/compiletests/ui/arch/subgroup/subgroup_composite_all_equals.rs b/tests/compiletests/ui/arch/subgroup/subgroup_composite_all_equals.rs
index 953a4429e8..27c84ffaaf 100644
--- a/tests/compiletests/ui/arch/subgroup/subgroup_composite_all_equals.rs
+++ b/tests/compiletests/ui/arch/subgroup/subgroup_composite_all_equals.rs
@@ -29,14 +29,15 @@ fn disassembly(my_struct: MyStruct) -> bool {
 
 #[spirv(compute(threads(32)))]
 pub fn main(
-    #[spirv(local_invocation_index)] inv_id: UVec3,
+    #[spirv(local_invocation_index)] inv_id: u32,
+    #[spirv(local_invocation_id)] inv_id_3d: UVec3,
     #[spirv(descriptor_set = 0, binding = 0, storage_buffer)] output: &mut u32,
 ) {
     unsafe {
         let my_struct = MyStruct {
-            a: inv_id.x as f32,
-            b: inv_id,
-            c: Nested(5i32 - inv_id.x as i32),
+            a: inv_id as f32,
+            b: inv_id_3d,
+            c: Nested(5i32 - inv_id as i32),
             d: Zst,
         };
 
diff --git a/tests/compiletests/ui/arch/subgroup/subgroup_composite_enum.rs b/tests/compiletests/ui/arch/subgroup/subgroup_composite_enum.rs
index ada500fb06..113e0f40fa 100644
--- a/tests/compiletests/ui/arch/subgroup/subgroup_composite_enum.rs
+++ b/tests/compiletests/ui/arch/subgroup/subgroup_composite_enum.rs
@@ -43,11 +43,11 @@ fn disassembly(my_struct: MyEnum, id: u32) -> MyEnum {
 
 #[spirv(compute(threads(32)))]
 pub fn main(
-    #[spirv(local_invocation_index)] inv_id: UVec3,
+    #[spirv(local_invocation_index)] inv_id: u32,
     #[spirv(descriptor_set = 0, binding = 0, storage_buffer)] output: &mut MyEnum,
 ) {
     unsafe {
-        let my_enum = MyEnum::from(inv_id.x % 3);
+        let my_enum = MyEnum::from(inv_id % 3);
         *output = disassembly(my_enum, 5);
     }
 }
diff --git a/tests/compiletests/ui/arch/subgroup/subgroup_composite_shuffle.rs b/tests/compiletests/ui/arch/subgroup/subgroup_composite_shuffle.rs
index a40c26175a..6315697c4b 100644
--- a/tests/compiletests/ui/arch/subgroup/subgroup_composite_shuffle.rs
+++ b/tests/compiletests/ui/arch/subgroup/subgroup_composite_shuffle.rs
@@ -29,14 +29,15 @@ fn disassembly(my_struct: MyStruct, id: u32) -> MyStruct {
 
 #[spirv(compute(threads(32)))]
 pub fn main(
-    #[spirv(local_invocation_index)] inv_id: UVec3,
+    #[spirv(local_invocation_index)] inv_id: u32,
+    #[spirv(local_invocation_id)] inv_id_3d: UVec3,
     #[spirv(descriptor_set = 0, binding = 0, storage_buffer)] output: &mut MyStruct,
 ) {
     unsafe {
         let my_struct = MyStruct {
-            a: inv_id.x as f32,
-            b: inv_id,
-            c: Nested(5i32 - inv_id.x as i32),
+            a: inv_id as f32,
+            b: inv_id_3d,
+            c: Nested(5i32 - inv_id as i32),
             d: Zst,
         };
 
diff --git a/tests/compiletests/ui/spirv-attr/all-builtins.rs b/tests/compiletests/ui/spirv-attr/all-builtins.rs
index 396fd850f4..4f5475d996 100644
--- a/tests/compiletests/ui/spirv-attr/all-builtins.rs
+++ b/tests/compiletests/ui/spirv-attr/all-builtins.rs
@@ -44,7 +44,7 @@ pub fn vertex(
     #[spirv(frag_stencil_ref_ext)] frag_stencil_ref_ext: &mut u32,
     #[spirv(instance_index)] instance_index: u32,
     #[spirv(layer_per_view_nv)] layer_per_view_nv: u32,
-    #[spirv(local_invocation_index)] local_invocation_index: UVec3,
+    #[spirv(local_invocation_index)] local_invocation_index: u32,
     #[spirv(mesh_view_count_nv)] mesh_view_count_nv: u32,
     #[spirv(mesh_view_indices_nv)] mesh_view_indices_nv: u32,
     #[spirv(point_size)] point_size: &mut u32,
diff --git a/tests/compiletests/ui/spirv-attr/local-invocation-index-type.rs b/tests/compiletests/ui/spirv-attr/local-invocation-index-type.rs
new file mode 100644
index 0000000000..c07ff05bff
--- /dev/null
+++ b/tests/compiletests/ui/spirv-attr/local-invocation-index-type.rs
@@ -0,0 +1,7 @@
+// build-fail
+
+use spirv_std::glam::UVec3;
+use spirv_std::spirv;
+
+#[spirv(compute(threads(1)))]
+pub fn main(#[spirv(local_invocation_index)] index: UVec3) {}
diff --git a/tests/compiletests/ui/spirv-attr/local-invocation-index-type.stderr b/tests/compiletests/ui/spirv-attr/local-invocation-index-type.stderr
new file mode 100644
index 0000000000..60469cd8fb
--- /dev/null
+++ b/tests/compiletests/ui/spirv-attr/local-invocation-index-type.stderr
@@ -0,0 +1,8 @@
+error: `#[spirv(local_invocation_index)]` must be a `u32`, not `spirv_std::glam::UVec3`
+  --> $DIR/local-invocation-index-type.rs:7:53
+   |
+LL | pub fn main(#[spirv(local_invocation_index)] index: UVec3) {}
+   |                                                     ^^^^^
+
+error: aborting due to 1 previous error
+