diff --git a/src/bitmap.c b/src/bitmap.c
index 98b53052..01064140 100644
--- a/src/bitmap.c
+++ b/src/bitmap.c
@@ -1,5 +1,5 @@
 /* ----------------------------------------------------------------------------
-Copyright (c) 2019-2021 Microsoft Research, Daan Leijen
+Copyright (c) 2019-2023 Microsoft Research, Daan Leijen
 This is free software; you can redistribute it and/or modify it under the
 terms of the MIT license. A copy of the license can be found in the file
 "LICENSE" at the root of this distribution.
diff --git a/src/segment-map.c b/src/segment-map.c
index 56b18531..4c2104bd 100644
--- a/src/segment-map.c
+++ b/src/segment-map.c
@@ -125,7 +125,7 @@ static mi_segment_t* _mi_segment_of(const void* p) {
 
 // Is this a valid pointer in our heap?
 static bool  mi_is_valid_pointer(const void* p) {
-  return (_mi_segment_of(p) != NULL);
+  return ((_mi_segment_of(p) != NULL) || (_mi_arena_contains(p)));
 }
 
 mi_decl_nodiscard mi_decl_export bool mi_is_in_heap_region(const void* p) mi_attr_noexcept {
diff --git a/test/test-stress.c b/test/test-stress.c
index c0de8910..0d6d0bc9 100644
--- a/test/test-stress.c
+++ b/test/test-stress.c
@@ -38,8 +38,8 @@ static int ITER    = 50;      // N full iterations destructing and re-creating a
 
 #define STRESS   // undefine for leak test
 
-static bool   allow_large_objects = true;    // allow very large objects?
-static size_t use_one_size = 0;              // use single object size of `N * sizeof(uintptr_t)`?
+static bool   allow_large_objects = false;    // allow very large objects? (set to `true` if SCALE>100)
+static size_t use_one_size = 0;               // use single object size of `N * sizeof(uintptr_t)`?
 
 
 // #define USE_STD_MALLOC
@@ -244,7 +244,10 @@ int main(int argc, char** argv) {
     long n = (strtol(argv[3], &end, 10));
     if (n > 0) ITER = n;
   }
-  printf("Using %d threads with a %d%% load-per-thread and %d iterations\n", THREADS, SCALE, ITER);
+  if (SCALE > 100) {
+    allow_large_objects = true;
+  }
+  printf("Using %d threads with a %d%% load-per-thread and %d iterations %s\n", THREADS, SCALE, ITER, (allow_large_objects ? "(allow large objects)" : ""));
   //mi_reserve_os_memory(1024*1024*1024ULL, false, true);
   //int res = mi_reserve_huge_os_pages(4,1);
   //printf("(reserve huge: %i\n)", res);