diff --git a/gc/mmtk/src/abi.rs b/gc/mmtk/src/abi.rs
index 1d7dc62a87..1e03dbf2f9 100644
--- a/gc/mmtk/src/abi.rs
+++ b/gc/mmtk/src/abi.rs
@@ -1,8 +1,12 @@
 use crate::api::RubyMutator;
-use crate::{extra_assert, Ruby};
+use crate::extra_assert;
+use crate::Ruby;
 use libc::c_int;
 use mmtk::scheduler::GCWorker;
-use mmtk::util::{Address, ObjectReference, VMMutatorThread, VMWorkerThread};
+use mmtk::util::Address;
+use mmtk::util::ObjectReference;
+use mmtk::util::VMMutatorThread;
+use mmtk::util::VMWorkerThread;
 
 // For the C binding
 pub const OBJREF_OFFSET: usize = 8;
diff --git a/gc/mmtk/src/collection.rs b/gc/mmtk/src/collection.rs
index 0b1221204c..83d046aef4 100644
--- a/gc/mmtk/src/collection.rs
+++ b/gc/mmtk/src/collection.rs
@@ -2,12 +2,17 @@ use crate::abi::GCThreadTLS;
 
 use crate::api::RubyMutator;
 use crate::heap::RubyHeapTrigger;
-use crate::{mmtk, upcalls, Ruby};
+use crate::mmtk;
+use crate::upcalls;
+use crate::Ruby;
 use mmtk::memory_manager;
 use mmtk::scheduler::*;
 use mmtk::util::heap::GCTriggerPolicy;
-use mmtk::util::{VMMutatorThread, VMThread, VMWorkerThread};
-use mmtk::vm::{Collection, GCThreadContext};
+use mmtk::util::VMMutatorThread;
+use mmtk::util::VMThread;
+use mmtk::util::VMWorkerThread;
+use mmtk::vm::Collection;
+use mmtk::vm::GCThreadContext;
 use std::sync::atomic::AtomicBool;
 use std::sync::atomic::Ordering;
 use std::thread;
diff --git a/gc/mmtk/src/heap/ruby_heap_trigger.rs b/gc/mmtk/src/heap/ruby_heap_trigger.rs
index 9215e2ebb0..fe1130043d 100644
--- a/gc/mmtk/src/heap/ruby_heap_trigger.rs
+++ b/gc/mmtk/src/heap/ruby_heap_trigger.rs
@@ -1,4 +1,5 @@
-use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
 
 use mmtk::util::heap::GCTriggerPolicy;
 use mmtk::util::heap::SpaceStats;
diff --git a/gc/mmtk/src/lib.rs b/gc/mmtk/src/lib.rs
index 0da6121883..0ee8f6752e 100644
--- a/gc/mmtk/src/lib.rs
+++ b/gc/mmtk/src/lib.rs
@@ -14,8 +14,11 @@ use std::sync::Mutex;
 use std::thread::ThreadId;
 
 use abi::RubyUpcalls;
-use binding::{RubyBinding, RubyBindingFast, RubyConfiguration};
-use mmtk::vm::slot::{SimpleSlot, UnimplementedMemorySlice};
+use binding::RubyBinding;
+use binding::RubyBindingFast;
+use binding::RubyConfiguration;
+use mmtk::vm::slot::SimpleSlot;
+use mmtk::vm::slot::UnimplementedMemorySlice;
 use mmtk::vm::VMBinding;
 use mmtk::MMTK;
 use once_cell::sync::OnceCell;
diff --git a/gc/mmtk/src/object_model.rs b/gc/mmtk/src/object_model.rs
index dd27f83612..d673ca11a0 100644
--- a/gc/mmtk/src/object_model.rs
+++ b/gc/mmtk/src/object_model.rs
@@ -1,10 +1,15 @@
 use std::ptr::copy_nonoverlapping;
 
-use crate::abi::{RubyObjectAccess, MIN_OBJ_ALIGN, OBJREF_OFFSET};
-use crate::{abi, Ruby};
+use crate::abi;
+use crate::abi::RubyObjectAccess;
+use crate::abi::MIN_OBJ_ALIGN;
+use crate::abi::OBJREF_OFFSET;
+use crate::Ruby;
 use mmtk::util::constants::BITS_IN_BYTE;
-use mmtk::util::copy::{CopySemantics, GCWorkerCopyContext};
-use mmtk::util::{Address, ObjectReference};
+use mmtk::util::copy::CopySemantics;
+use mmtk::util::copy::GCWorkerCopyContext;
+use mmtk::util::Address;
+use mmtk::util::ObjectReference;
 use mmtk::vm::*;
 
 pub struct VMObjectModel {}
diff --git a/gc/mmtk/src/pinning_registry.rs b/gc/mmtk/src/pinning_registry.rs
index 7f67bbeef5..71cf73eaf9 100644
--- a/gc/mmtk/src/pinning_registry.rs
+++ b/gc/mmtk/src/pinning_registry.rs
@@ -1,13 +1,16 @@
 use std::sync::Mutex;
 
-use mmtk::{
-    memory_manager,
-    scheduler::{GCWork, GCWorker, WorkBucketStage},
-    util::{ObjectReference, VMWorkerThread},
-    MMTK,
-};
+use mmtk::memory_manager;
+use mmtk::scheduler::GCWork;
+use mmtk::scheduler::GCWorker;
+use mmtk::scheduler::WorkBucketStage;
+use mmtk::util::ObjectReference;
+use mmtk::util::VMWorkerThread;
+use mmtk::MMTK;
 
-use crate::{abi::GCThreadTLS, upcalls, Ruby};
+use crate::abi::GCThreadTLS;
+use crate::upcalls;
+use crate::Ruby;
 
 pub struct PinningRegistry {
     pinning_objs: Mutex<Vec<ObjectReference>>,
diff --git a/gc/mmtk/src/scanning.rs b/gc/mmtk/src/scanning.rs
index eca4769e2f..be834bdd0b 100644
--- a/gc/mmtk/src/scanning.rs
+++ b/gc/mmtk/src/scanning.rs
@@ -1,10 +1,18 @@
 use crate::abi::GCThreadTLS;
 
+use crate::upcalls;
 use crate::utils::ChunkedVecCollector;
-use crate::{upcalls, Ruby, RubySlot};
-use mmtk::scheduler::{GCWork, GCWorker, WorkBucketStage};
-use mmtk::util::{ObjectReference, VMWorkerThread};
-use mmtk::vm::{ObjectTracer, RootsWorkFactory, Scanning, SlotVisitor};
+use crate::Ruby;
+use crate::RubySlot;
+use mmtk::scheduler::GCWork;
+use mmtk::scheduler::GCWorker;
+use mmtk::scheduler::WorkBucketStage;
+use mmtk::util::ObjectReference;
+use mmtk::util::VMWorkerThread;
+use mmtk::vm::ObjectTracer;
+use mmtk::vm::RootsWorkFactory;
+use mmtk::vm::Scanning;
+use mmtk::vm::SlotVisitor;
 use mmtk::Mutator;
 
 pub struct VMScanning {}
diff --git a/gc/mmtk/src/utils.rs b/gc/mmtk/src/utils.rs
index 71a7ae8dd2..d1979eaf58 100644
--- a/gc/mmtk/src/utils.rs
+++ b/gc/mmtk/src/utils.rs
@@ -1,7 +1,10 @@
-use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
 
 use atomic_refcell::AtomicRefCell;
-use mmtk::scheduler::{GCWork, GCWorker, WorkBucketStage};
+use mmtk::scheduler::GCWork;
+use mmtk::scheduler::GCWorker;
+use mmtk::scheduler::WorkBucketStage;
 
 use crate::Ruby;
 use sysinfo::System;
diff --git a/gc/mmtk/src/weak_proc.rs b/gc/mmtk/src/weak_proc.rs
index 3184c4f6d1..c8ad944633 100644
--- a/gc/mmtk/src/weak_proc.rs
+++ b/gc/mmtk/src/weak_proc.rs
@@ -1,12 +1,14 @@
 use std::sync::Mutex;
 
-use mmtk::{
-    scheduler::{GCWork, GCWorker, WorkBucketStage},
-    util::ObjectReference,
-    vm::ObjectTracerContext,
-};
+use mmtk::scheduler::GCWork;
+use mmtk::scheduler::GCWorker;
+use mmtk::scheduler::WorkBucketStage;
+use mmtk::util::ObjectReference;
+use mmtk::vm::ObjectTracerContext;
 
-use crate::{abi::GCThreadTLS, upcalls, Ruby};
+use crate::abi::GCThreadTLS;
+use crate::upcalls;
+use crate::Ruby;
 
 pub struct WeakProcessor {
     /// Objects that needs `obj_free` called when dying.