diff --git a/racket/src/racket/gc2/newgc.c b/racket/src/racket/gc2/newgc.c
index 40748c32bc..ff7efcbec8 100644
--- a/racket/src/racket/gc2/newgc.c
+++ b/racket/src/racket/gc2/newgc.c
@@ -3580,7 +3580,7 @@ void GC_mark2(void *pp, struct NewGC *gc)
 
       size = gcWORDS_TO_BYTES(ohead->size);
 
-      if (AGE_GEN_0_TO_GEN_HALF(gc) && (page->generation == AGE_GEN_0) && !gc->gc_full) {
+      if (gc->use_gen_half && (page->generation == AGE_GEN_0)) {
         /* move to generation 1/2 */
         work = gc->gen_half.curr_alloc_page;
         if (!work || (work->size + size > GEN0_PAGE_SIZE)) {
@@ -5023,6 +5023,8 @@ static void garbage_collect(NewGC *gc, int force_full, int no_full, int switchin
   gc->in_unsafe_allocation_mode = 1;
   gc->unsafe_allocation_abort = out_of_memory_gc;
 
+  gc->use_gen_half = !gc->gc_full && AGE_GEN_0_TO_GEN_HALF(gc);
+
   if (gc->gc_full)
     gc->phantom_count = 0;
   else if (gc->memory_in_use > gc->phantom_count) {
diff --git a/racket/src/racket/gc2/newgc.h b/racket/src/racket/gc2/newgc.h
index 0e86dbc228..a979c75c2a 100644
--- a/racket/src/racket/gc2/newgc.h
+++ b/racket/src/racket/gc2/newgc.h
@@ -193,6 +193,7 @@ typedef struct NewGC {
   unsigned char full_needed_for_finalization :1;
   unsigned char no_further_modifications     :1;
   unsigned char gc_full                      :1; /* a flag saying if this is a full/major collection */
+  unsigned char use_gen_half                 :1;
   unsigned char running_finalizers           :1;
   unsigned char back_pointers                :1;
   unsigned char need_fixup                   :1;