diff --git a/CHANGES.md b/CHANGES.md
index 7e1870d..8f7d154 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,7 @@
 # Changes in Mini-XML 3.2.1
 
 - Fixed `MXML_MINOR_VERSION` value in "mxml.h" (Issue #285)
+- Fixed POSIX threading support for MingW (Issue #287)
 - Fixed some minor memory leaks found by Coverity.
 
 
diff --git a/mxml-private.c b/mxml-private.c
index 726acc9..8c1c58d 100644
--- a/mxml-private.c
+++ b/mxml-private.c
@@ -3,7 +3,7 @@
  *
  * https://www.msweet.org/mxml
  *
- * Copyright © 2003-2019 by Michael R Sweet.
+ * Copyright © 2003-2021 by Michael R Sweet.
  *
  * Licensed under Apache License v2.0.  See the file "LICENSE" for more
  * information.
@@ -140,7 +140,7 @@ mxml_real_cb(mxml_node_t *node)		/* I - Current node */
 #ifdef HAVE_PTHREAD_H			/**** POSIX threading ****/
 #  include <pthread.h>
 
-static pthread_key_t	_mxml_key = -1;	/* Thread local storage key */
+static pthread_key_t	_mxml_key;	/* Thread local storage key */
 static pthread_once_t	_mxml_key_once = PTHREAD_ONCE_INIT;
 					/* One-time initialization object */
 static void		_mxml_init(void);
@@ -168,14 +168,10 @@ _MXML_FINI(void)
   _mxml_global_t	*global;	/* Global data */
 
 
-  if (_mxml_key != -1)
-  {
-    if ((global = (_mxml_global_t *)pthread_getspecific(_mxml_key)) != NULL)
-      _mxml_destructor(global);
+  if ((global = (_mxml_global_t *)pthread_getspecific(_mxml_key)) != NULL)
+    _mxml_destructor(global);
 
-    pthread_key_delete(_mxml_key);
-    _mxml_key = -1;
-  }
+  pthread_key_delete(_mxml_key);
 }