diff --git a/include/mimalloc/types.h b/include/mimalloc/types.h
index 72c8d0a7..53c543d0 100644
--- a/include/mimalloc/types.h
+++ b/include/mimalloc/types.h
@@ -324,7 +324,7 @@ typedef struct mi_page_s {
 // (Except for large pages since huge objects are allocated in 4MiB chunks)
 #define MI_SMALL_MAX_OBJ_SIZE             ((MI_SMALL_PAGE_SIZE-MI_PAGE_INFO_SIZE)/8)   // < 11 KiB
 #define MI_MEDIUM_MAX_OBJ_SIZE            ((MI_MEDIUM_PAGE_SIZE-MI_PAGE_INFO_SIZE)/8)  // < 128 KiB
-#define MI_LARGE_MAX_OBJ_SIZE             ((MI_LARGE_PAGE_SIZE-MI_PAGE_INFO_SIZE)/4)   // < 1 MiB
+#define MI_LARGE_MAX_OBJ_SIZE             ((MI_LARGE_PAGE_SIZE-MI_PAGE_INFO_SIZE)/8)   // < 1 MiB
 #define MI_LARGE_MAX_OBJ_WSIZE            (MI_LARGE_MAX_OBJ_SIZE/MI_SIZE_SIZE)
 
 
diff --git a/src/arena.c b/src/arena.c
index b2113ec0..bc88acf3 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -280,7 +280,7 @@ static bool mi_arena_reserve(mi_subproc_t* subproc, size_t req_size, bool allow_
 
   if (arena_count >= 1 && arena_count <= 128) {
     // scale up the arena sizes exponentially every 4 entries
-    const size_t multiplier = (size_t)1 << _mi_clamp(arena_count/2, 0, 16);
+    const size_t multiplier = (size_t)1 << _mi_clamp(arena_count/4, 0, 16);
     size_t reserve = 0;
     if (!mi_mul_overflow(multiplier, arena_reserve, &reserve)) {
       arena_reserve = reserve;