diff --git a/include/mimalloc.h b/include/mimalloc.h
index cb408acc..e91b24a3 100644
--- a/include/mimalloc.h
+++ b/include/mimalloc.h
@@ -318,12 +318,12 @@ mi_decl_export int  mi_reserve_huge_os_pages(size_t pages, double max_secs, size
 
 typedef enum mi_option_e {
   // stable options
-  mi_option_show_errors,
-  mi_option_show_stats,
-  mi_option_verbose,
-  // some of the following options are experimental
+  mi_option_show_errors,              // print error messages
+  mi_option_show_stats,               // print statistics on termination
+  mi_option_verbose,                  // print verbose messages
+  // the following options are experimental (see src/options.h)
   // (deprecated options are kept for binary backward compatibility with v1.x versions)
-  mi_option_eager_commit,
+  mi_option_segment_eager_commit,
   mi_option_arena_eager_commit,
   mi_option_purge_decommits,
   mi_option_large_os_pages,           // use large (2MiB) OS pages, implies eager commit
@@ -342,13 +342,18 @@ typedef enum mi_option_e {
   mi_option_max_errors,
   mi_option_max_warnings,
   mi_option_max_segment_reclaim,
-  mi_option_allow_purge,
   mi_option_deprecated_segment_decommit_delay,  
   mi_option_purge_extend_delay,
   mi_option_destroy_on_exit,
   mi_option_arena_reserve,
   mi_option_arena_purge_delay,
-  _mi_option_last
+  mi_option_allow_purge,
+  _mi_option_last,
+  // legacy options
+  mi_option_eager_commit = mi_option_segment_eager_commit,
+  mi_option_eager_region_commit = mi_option_arena_eager_commit,
+  mi_option_reset_decommits = mi_option_purge_decommits,
+  mi_option_reset_delay = mi_option_purge_delay
 } mi_option_t;
 
 
diff --git a/include/mimalloc/internal.h b/include/mimalloc/internal.h
index e97e7d91..9dbd128c 100644
--- a/include/mimalloc/internal.h
+++ b/include/mimalloc/internal.h
@@ -99,6 +99,7 @@ bool       _mi_os_commit(void* p, size_t size, bool* is_zero, mi_stats_t* stats)
 bool       _mi_os_decommit(void* addr, size_t size, mi_stats_t* stats);
 bool       _mi_os_protect(void* addr, size_t size);
 bool       _mi_os_unprotect(void* addr, size_t size);
+bool       _mi_os_purge(void* p, size_t size, mi_stats_t* stats);
 
 void*      _mi_os_alloc_aligned(size_t size, size_t alignment, bool commit, bool* large, mi_stats_t* stats);
 void*      _mi_os_alloc_aligned_offset(size_t size, size_t alignment, size_t align_offset, bool commit, bool* large, mi_stats_t* tld_stats);
diff --git a/src/arena.c b/src/arena.c
index 134a6227..c29da473 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -1,3 +1,5 @@
+
+
 /* ----------------------------------------------------------------------------
 Copyright (c) 2019-2022, Microsoft Research, Daan Leijen
 This is free software; you can redistribute it and/or modify it under the
@@ -190,7 +192,7 @@ static mi_decl_noinline void* mi_arena_alloc_from(mi_arena_t* arena, size_t aren
     *commit = _mi_bitmap_is_claimed_across(arena->blocks_committed, arena->field_count, needed_bcount, bitmap_index);
   }
   
-  // mi_track_mem_undefined(p,needed_bcount*MI_ARENA_BLOCK_SIZE);
+  mi_track_mem_undefined(p,needed_bcount*MI_ARENA_BLOCK_SIZE); // todo: should not be needed?
   return p;
 }
 
@@ -752,3 +754,4 @@ int mi_reserve_huge_os_pages(size_t pages, double max_secs, size_t* pages_reserv
   if (err==0 && pages_reserved!=NULL) *pages_reserved = pages;
   return err;
 }
+
diff --git a/src/options.c b/src/options.c
index bb11b6a5..2e3e98a9 100644
--- a/src/options.c
+++ b/src/options.c
@@ -82,7 +82,6 @@ static mi_option_desc_t options[_mi_option_last] =
   { 16,   UNINIT, MI_OPTION(max_errors) },        // maximum errors that are output
   { 16,   UNINIT, MI_OPTION(max_warnings) },      // maximum warnings that are output
   { 8,    UNINIT, MI_OPTION(max_segment_reclaim)},// max. number of segment reclaims from the abandoned segments per try.  
-  { 1,    UNINIT, MI_OPTION_LEGACY(allow_purge, allow_decommit) },    // decommit slices when no longer used (after decommit_delay milli-seconds)
   { 100,  UNINIT, MI_OPTION(deprecated_segment_decommit_delay) }, // decommit delay in milli-seconds for freed segments
   { 1,    UNINIT, MI_OPTION_LEGACY(purge_extend_delay, decommit_extend_delay) },
   { 0,    UNINIT, MI_OPTION(destroy_on_exit)},    // release all OS memory on process exit; careful with dangling pointer or after-exit frees!
@@ -91,7 +90,8 @@ static mi_option_desc_t options[_mi_option_last] =
   #else
   {  128L*1024L, UNINIT, MI_OPTION(arena_reserve) },   
   #endif
-  { 100, UNINIT, MI_OPTION(arena_purge_delay) }  // reset/decommit delay in milli-seconds for arena allocation
+  { 100, UNINIT, MI_OPTION(arena_purge_delay) }, // reset/decommit delay in milli-seconds for arena allocation
+  { 1,   UNINIT, MI_OPTION(allow_purge) }        // allow decommit/reset to free (physical) memory back to the OS
 };
 
 static void mi_option_init(mi_option_desc_t* desc);