diff --git a/src/os.c b/src/os.c
index 507d9971..26b8bcd2 100644
--- a/src/os.c
+++ b/src/os.c
@@ -846,7 +846,7 @@ static bool mi_os_commitx(void* addr, size_t size, bool commit, bool conservativ
   if (err != 0) { err = errno; }
   #endif
   if (err != 0) {
-    _mi_warning_message("%s error: start: %p, csize: 0x%x, err: %i\n", commit ? "commit" : "decommit", start, csize, err);
+    _mi_warning_message("%s error: start: %p, csize: 0x%zx, err: %i\n", commit ? "commit" : "decommit", start, csize, err);
     mi_mprotect_hint(err);
   }
   mi_assert_internal(err == 0);
@@ -916,7 +916,7 @@ static bool mi_os_resetx(void* addr, size_t size, bool reset, mi_stats_t* stats)
   int err = madvise(start, csize, MADV_DONTNEED);
 #endif
   if (err != 0) {
-    _mi_warning_message("madvise reset error: start: %p, csize: 0x%x, errno: %i\n", start, csize, errno);
+    _mi_warning_message("madvise reset error: start: %p, csize: 0x%zx, errno: %i\n", start, csize, errno);
   }
   //mi_assert(err == 0);
   if (err != 0) return false;
@@ -975,7 +975,7 @@ static  bool mi_os_protectx(void* addr, size_t size, bool protect) {
   if (err != 0) { err = errno; }
 #endif
   if (err != 0) {
-    _mi_warning_message("mprotect error: start: %p, csize: 0x%x, err: %i\n", start, csize, err);
+    _mi_warning_message("mprotect error: start: %p, csize: 0x%zx, err: %i\n", start, csize, err);
     mi_mprotect_hint(err);
   }
   return (err == 0);
diff --git a/src/stats.c b/src/stats.c
index 115d938e..6d486f42 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -327,7 +327,7 @@ static void _mi_stats_print(mi_stats_t* stats, mi_output_fun* out0, void* arg0)
   mi_stat_counter_print(&stats->commit_calls, "commits", out, arg);
   mi_stat_print(&stats->threads, "threads", -1, out, arg);
   mi_stat_counter_print_avg(&stats->searches, "searches", out, arg);
-  _mi_fprintf(out, arg, "%10s: %7i\n", "numa nodes", _mi_os_numa_node_count());
+  _mi_fprintf(out, arg, "%10s: %7zu\n", "numa nodes", _mi_os_numa_node_count());
   
   mi_msecs_t elapsed;
   mi_msecs_t user_time;