diff --git a/crates/wgpu_playground_core/tests/buffer_integration_test.rs b/crates/wgpu_playground_core/tests/buffer_integration_test.rs
index aa5db8c..c6a6a95 100644
--- a/crates/wgpu_playground_core/tests/buffer_integration_test.rs
+++ b/crates/wgpu_playground_core/tests/buffer_integration_test.rs
@@ -779,9 +779,8 @@ fn test_buffer_map_write_modify_read() {
         BufferOps::map_write(&write_buffer).await.unwrap();
         {
             let mut view = BufferOps::get_mapped_range_mut(&write_buffer);
-            for (i, byte) in view.iter_mut().enumerate() {
-                *byte = (i % 256) as u8;
-            }
+            let data: Vec<u8> = (0..256).map(|i| (i % 256) as u8).collect();
+            view.copy_from_slice(&data);
         }
         BufferOps::unmap(&write_buffer);
 
diff --git a/crates/wgpu_playground_examples/examples/lighting_shadows.rs b/crates/wgpu_playground_examples/examples/lighting_shadows.rs
index 8e29db3..1afc5bf 100644
--- a/crates/wgpu_playground_examples/examples/lighting_shadows.rs
+++ b/crates/wgpu_playground_examples/examples/lighting_shadows.rs
@@ -501,9 +501,9 @@ fn main() {
     let main_pipeline_layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
         label: Some("Main Pipeline Layout"),
         bind_group_layouts: &[
-            &camera_bind_group_layout,
-            &light_bind_group_layout,
-            &shadow_map_bind_group_layout,
+            Some(&camera_bind_group_layout),
+            Some(&light_bind_group_layout),
+            Some(&shadow_map_bind_group_layout),
         ],
         immediate_size: 0,
     });