diff --git a/include/mimalloc-internal.h b/include/mimalloc-internal.h
index cd3b0fde..cfe5847b 100644
--- a/include/mimalloc-internal.h
+++ b/include/mimalloc-internal.h
@@ -80,6 +80,7 @@ bool       _mi_os_decommit(void* p, size_t size, mi_stats_t* stats);
 bool       _mi_os_reset(void* p, size_t size, mi_stats_t* stats);
 bool       _mi_os_unreset(void* p, size_t size, bool* is_zero, mi_stats_t* stats);
 size_t     _mi_os_good_alloc_size(size_t size);
+bool       _mi_os_has_overcommit(void);
 
 // arena.c
 void*      _mi_arena_alloc_aligned(size_t size, size_t alignment, bool* commit, bool* large, bool* is_pinned, bool* is_zero, size_t* memid, mi_os_tld_t* tld);
diff --git a/src/os.c b/src/os.c
index 31ad4119..169680a1 100644
--- a/src/os.c
+++ b/src/os.c
@@ -90,6 +90,10 @@ static size_t large_os_page_size = 0;
 // set dynamically in _mi_os_init (and if true we use MAP_NORESERVE)
 static bool os_overcommit = true;
 
+bool _mi_os_has_overcommit(void) {
+  return os_overcommit;
+}
+
 // OS (small) page size
 size_t _mi_os_page_size() {
   return os_page_size;
@@ -463,7 +467,7 @@ static void* mi_unix_mmap(void* addr, size_t size, size_t try_alignment, int pro
   #endif
   const int fd = mi_unix_mmap_fd();
   int flags = MAP_PRIVATE | MAP_ANONYMOUS;
-  if (os_overcommit) {
+  if (_mi_os_has_overcommit()) {
     flags |= MAP_NORESERVE;
   }  
   #if defined(PROT_MAX)
diff --git a/src/segment.c b/src/segment.c
index 30c2e22b..7b2fa28e 100644
--- a/src/segment.c
+++ b/src/segment.c
@@ -579,7 +579,7 @@ static void mi_segment_perhaps_decommit(mi_segment_t* segment, uint8_t* p, size_
     else if (segment->decommit_expire <= now) {
       // previous decommit mask already expired
       // mi_segment_delayed_decommit(segment, true, stats);
-      segment->decommit_expire = now + 5; // wait a tiny bit longer in case there is a series of free's
+      segment->decommit_expire = now + (mi_option_get(mi_option_reset_delay) / 8); // wait a tiny bit longer in case there is a series of free's
     }
     else {
       // previous decommit mask is not yet expired
@@ -809,7 +809,9 @@ static mi_segment_t* mi_segment_init(mi_segment_t* segment, size_t required, mi_
   const size_t segment_size = segment_slices * MI_SEGMENT_SLICE_SIZE;
 
   // Commit eagerly only if not the first N lazy segments (to reduce impact of many threads that allocate just a little)
-  const bool eager_delay = (_mi_current_thread_count() > 2 && tld->count < (size_t)mi_option_get(mi_option_eager_commit_delay));
+  const bool eager_delay = (!_mi_os_has_overcommit() &&             // never delay on overcommit systems
+                            _mi_current_thread_count() > 2 &&       // do not delay for the first N threads
+                            tld->count < (size_t)mi_option_get(mi_option_eager_commit_delay));
   const bool eager = !eager_delay && mi_option_is_enabled(mi_option_eager_commit);
   bool commit = eager || (required > 0);