diff --git a/wgpu-core/src/command/mod.rs b/wgpu-core/src/command/mod.rs
index 9dbb9ed5de..6a2fe298ae 100644
--- a/wgpu-core/src/command/mod.rs
+++ b/wgpu-core/src/command/mod.rs
@@ -90,7 +90,17 @@ impl<A: hal::Api> BakedCommands<A> {
                 .get_mut(buffer_use.id)
                 .map_err(|_| DestroyedBufferError(buffer_use.id))?;
 
-            let uninitialized_ranges = buffer.initialization_status.drain(buffer_use.range.clone());
+            // align the end to 4
+            let end_remainder = buffer_use.range.end % wgt::COPY_BUFFER_ALIGNMENT;
+            let end = if end_remainder == 0 {
+                buffer_use.range.end
+            } else {
+                buffer_use.range.end + wgt::COPY_BUFFER_ALIGNMENT - end_remainder
+            };
+            let uninitialized_ranges = buffer
+                .initialization_status
+                .drain(buffer_use.range.start..end);
+
             match buffer_use.kind {
                 MemoryInitKind::ImplicitlyInitialized => {
                     uninitialized_ranges.for_each(drop);
@@ -140,8 +150,8 @@ impl<A: hal::Api> BakedCommands<A> {
             }
 
             for range in ranges.iter() {
-                assert!(range.start % 4 == 0, "Buffer {:?} has an uninitialized range with a start not aligned to 4 (start was {})", raw_buf, range.start);
-                assert!(range.end % 4 == 0, "Buffer {:?} has an uninitialized range with an end not aligned to 4 (end was {})", raw_buf, range.end);
+                assert!(range.start % wgt::COPY_BUFFER_ALIGNMENT == 0, "Buffer {:?} has an uninitialized range with a start not aligned to 4 (start was {})", raw_buf, range.start);
+                assert!(range.end % wgt::COPY_BUFFER_ALIGNMENT == 0, "Buffer {:?} has an uninitialized range with an end not aligned to 4 (end was {})", raw_buf, range.end);
 
                 unsafe {
                     self.encoder.clear_buffer(raw_buf, range.clone());
diff --git a/wgpu-core/src/device/mod.rs b/wgpu-core/src/device/mod.rs
index 277a28cc6c..a874f65025 100644
--- a/wgpu-core/src/device/mod.rs
+++ b/wgpu-core/src/device/mod.rs
@@ -160,6 +160,8 @@ fn map_buffer<A: hal::Api>(
         _ => None,
     };
 
+    assert_eq!(offset % wgt::COPY_BUFFER_ALIGNMENT, 0);
+    assert_eq!(size % wgt::COPY_BUFFER_ALIGNMENT, 0);
     // Zero out uninitialized parts of the mapping. (Spec dictates all resources behave as if they were initialized with zero)
     //
     // If this is a read mapping, ideally we would use a `clear_buffer` command before reading the data from GPU (i.e. `invalidate_range`).
@@ -510,13 +512,19 @@ impl<A: HalApi> Device<A> {
         } else {
             desc.size
         };
+        let clear_remainder = actual_size % wgt::COPY_BUFFER_ALIGNMENT;
+        let aligned_size = if clear_remainder != 0 {
+            actual_size + wgt::COPY_BUFFER_ALIGNMENT - clear_remainder
+        } else {
+            actual_size
+        };
 
         let mut memory_flags = hal::MemoryFlags::empty();
         memory_flags.set(hal::MemoryFlags::TRANSIENT, transient);
 
         let hal_desc = hal::BufferDescriptor {
             label: desc.label.borrow_option(),
-            size: actual_size,
+            size: aligned_size,
             usage,
             memory_flags,
         };
@@ -1323,9 +1331,10 @@ impl<A: HalApi> Device<A> {
             return Err(Error::BindingZeroSize(bb.buffer_id));
         }
 
+        assert_eq!(bb.offset % wgt::COPY_BUFFER_ALIGNMENT, 0);
         used_buffer_ranges.extend(buffer.initialization_status.create_action(
             bb.buffer_id,
-            bb.offset..(bb.offset + bind_size),
+            bb.offset..bb.offset + bind_size,
             MemoryInitKind::NeedsInitializedMemory,
         ));
 
@@ -2771,6 +2780,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
                     }
                 };
 
+                assert_eq!(buffer.size % wgt::COPY_BUFFER_ALIGNMENT, 0);
                 // Zero initialize memory and then mark both staging and buffer as initialized
                 // (it's guaranteed that this is the case by the time the buffer is usable)
                 unsafe { ptr::write_bytes(mapping.ptr.as_ptr(), 0, buffer.size as usize) };
diff --git a/wgpu-core/src/init_tracker/mod.rs b/wgpu-core/src/init_tracker/mod.rs
index dd6a6cc32d..527cb3d72a 100644
--- a/wgpu-core/src/init_tracker/mod.rs
+++ b/wgpu-core/src/init_tracker/mod.rs
@@ -14,7 +14,7 @@
 //      therefore this leads to a `MemoryInitKind.ImplicitlyInitialized` action, exactly like a read would.
 
 use smallvec::SmallVec;
-use std::{iter, ops::Range};
+use std::{fmt, iter, ops::Range};
 
 mod buffer;
 //mod texture;
@@ -46,7 +46,7 @@ pub(crate) struct InitTracker<Idx: Ord + Copy + Default> {
     uninitialized_ranges: UninitializedRangeVec<Idx>,
 }
 
-pub(crate) struct InitTrackerDrain<'a, Idx: Ord + Copy> {
+pub(crate) struct InitTrackerDrain<'a, Idx: fmt::Debug + Ord + Copy> {
     uninitialized_ranges: &'a mut UninitializedRangeVec<Idx>,
     drain_range: Range<Idx>,
     first_index: usize,
@@ -55,7 +55,7 @@ pub(crate) struct InitTrackerDrain<'a, Idx: Ord + Copy> {
 
 impl<'a, Idx> Iterator for InitTrackerDrain<'a, Idx>
 where
-    Idx: Ord + Copy,
+    Idx: fmt::Debug + Ord + Copy,
 {
     type Item = Range<Idx>;
 
@@ -78,7 +78,6 @@ where
             if num_affected == 0 {
                 return None;
             }
-
             let first_range = &mut self.uninitialized_ranges[self.first_index];
 
             // Split one "big" uninitialized range?
@@ -118,7 +117,7 @@ where
 
 impl<Idx> InitTracker<Idx>
 where
-    Idx: Ord + Copy + Default,
+    Idx: fmt::Debug + Ord + Copy + Default,
 {
     pub(crate) fn new(size: Idx) -> Self {
         Self {