diff --git a/src/nofl-space.h b/src/nofl-space.h
index bd9516cab..1f2f17765 100644
--- a/src/nofl-space.h
+++ b/src/nofl-space.h
@@ -944,17 +944,17 @@ nofl_space_prepare_gc(struct nofl_space *space, enum gc_collection_kind kind) {
 
 static void
 nofl_space_start_gc(struct nofl_space *space, enum gc_collection_kind gc_kind) {
-  GC_ASSERT_EQ(nofl_block_count(&space->partly_full), 0);
   GC_ASSERT_EQ(nofl_block_count(&space->to_sweep), 0);
 
   // Any block that was the target of allocation in the last cycle will need to
   // be swept next cycle.
   uintptr_t block;
+  while ((block = nofl_pop_block(&space->partly_full)))
+    nofl_push_block(&space->to_sweep, block);
   while ((block = nofl_pop_block(&space->full)))
     nofl_push_block(&space->to_sweep, block);
 
   if (gc_kind != GC_COLLECTION_MINOR) {
-    uintptr_t block;
     while ((block = nofl_pop_block(&space->promoted)))
       nofl_push_block(&space->to_sweep, block);
     while ((block = nofl_pop_block(&space->old)))
diff --git a/src/whippet.c b/src/whippet.c
index 1a00939b1..05597b4f8 100644
--- a/src/whippet.c
+++ b/src/whippet.c
@@ -247,6 +247,7 @@ add_mutator(struct gc_heap *heap, struct gc_mutator *mut) {
 
 static void
 remove_mutator(struct gc_heap *heap, struct gc_mutator *mut) {
+  nofl_allocator_finish(&mut->allocator, heap_nofl_space(heap));
   MUTATOR_EVENT(mut, mutator_removed);
   mut->heap = NULL;
   heap_lock(heap);
@@ -621,7 +622,8 @@ wait_for_mutators_to_stop(struct gc_heap *heap) {
     pthread_cond_wait(&heap->collector_cond, &heap->lock);
 }
 
-static void trace_mutator_conservative_roots_after_stop(struct gc_heap *heap) {
+static void
+trace_mutator_conservative_roots_after_stop(struct gc_heap *heap) {
   int active_mutators_already_marked = heap_should_mark_while_stopping(heap);
   if (!active_mutators_already_marked)
     for (struct gc_mutator *mut = atomic_load(&heap->mutator_trace_list);
@@ -654,10 +656,8 @@ trace_mutator_roots_after_stop(struct gc_heap *heap) {
   }
   atomic_store(&heap->mutator_trace_list, NULL);
 
-  for (struct gc_mutator *mut = heap->inactive_mutators; mut; mut = mut->next) {
-    nofl_allocator_finish(&mut->allocator, heap_nofl_space(heap));
+  for (struct gc_mutator *mut = heap->inactive_mutators; mut; mut = mut->next)
     trace_mutator_roots_with_lock(mut);
-  }
 }
 
 static void
@@ -1323,6 +1323,7 @@ void gc_finish_for_thread(struct gc_mutator *mut) {
 
 static void deactivate_mutator(struct gc_heap *heap, struct gc_mutator *mut) {
   GC_ASSERT(mut->next == NULL);
+  nofl_allocator_finish(&mut->allocator, heap_nofl_space(heap));
   heap_lock(heap);
   mut->next = heap->inactive_mutators;
   heap->inactive_mutators = mut;