diff --git a/src/init.c b/src/init.c
index e691df7f..37d2e1c4 100644
--- a/src/init.c
+++ b/src/init.c
@@ -473,7 +473,9 @@ static void mi_process_load(void) {
   MI_UNUSED(dummy);
   #endif
   os_preloading = false;
-  atexit(&mi_process_done);
+  #if !(defined(_WIN32) && defined(MI_SHARED_LIB))  // use Dll process detach (see below) instead of atexit (issue #521)
+  atexit(&mi_process_done);  
+  #endif
   _mi_options_init();
   mi_process_init();
   //mi_stats_reset();-
@@ -585,9 +587,14 @@ static void mi_process_done(void) {
     if (reason==DLL_PROCESS_ATTACH) {
       mi_process_load();
     }
-    else if (reason==DLL_THREAD_DETACH) {
-      if (!mi_is_redirected()) mi_thread_done();
+    else if (reason==DLL_PROCESS_DETACH) {
+      mi_process_done();
     }
+    else if (reason==DLL_THREAD_DETACH) {
+      if (!mi_is_redirected()) {
+        mi_thread_done();
+      }
+    }    
     return TRUE;
   }