diff --git a/winsup/mingw/ChangeLog b/winsup/mingw/ChangeLog
index 711906db1..d8a9d4e1a 100644
--- a/winsup/mingw/ChangeLog
+++ b/winsup/mingw/ChangeLog
@@ -1,3 +1,12 @@
+2011-08-27  Keith Marshall  <keithmarshall@users.sourceforge.net>
+
+	Don't expose implementation detail for opaque DIRENT structures.
+
+	* include/dirent.h (DIR, _WDIR): Declare as opaque data types.
+	(__dirstream_t, __wdirstream_t): Add these tags for their underlying
+	structures, respectively; move their detailed declarations to...
+	* mingwex/dirent.c: ...here.
+
 2011-08-23 Chris Sutcliffe <ir0nh34d@users.sourceforge.net>
 
 	* include/_mingw.h: Increment version to 3.20.
diff --git a/winsup/mingw/include/dirent.h b/winsup/mingw/include/dirent.h
index 44fb1c0a8..7d2af2b19 100644
--- a/winsup/mingw/include/dirent.h
+++ b/winsup/mingw/include/dirent.h
@@ -28,34 +28,10 @@ struct dirent
 };
 
 /*
- * This is an internal data structure. Good programmers will not use it
- * except as an argument to one of the functions below.
- * dd_stat field is now int (was short in older versions).
+ * This opaque data type represents the private structure
+ * through which a directory stream is referenced.
  */
-typedef struct
-{
-	/* disk transfer area for this dir */
-	struct _finddata_t	dd_dta;
-
-	/* dirent struct to return from dir (NOTE: this makes this thread
-	 * safe as long as only one thread uses a particular DIR struct at
-	 * a time) */
-	struct dirent		dd_dir;
-
-	/* _findnext handle */
-	intptr_t		dd_handle;
-
-	/*
-	 * Status of search:
-	 *   0 = not started yet (next entry to read is first entry)
-	 *  -1 = off the end
-	 *   positive = 0 based index of next entry
-	 */
-	int			dd_stat;
-
-	/* given path for dir with search pattern (struct is extended) */
-	char			dd_name[1];
-} DIR;
+typedef struct __dirstream_t DIR;
 
 DIR* __cdecl __MINGW_NOTHROW opendir (const char*);
 struct dirent* __cdecl __MINGW_NOTHROW readdir (DIR*);
@@ -76,33 +52,10 @@ struct _wdirent
 };
 
 /*
- * This is an internal data structure. Good programmers will not use it
- * except as an argument to one of the functions below.
+ * This opaque data type represents the private structure
+ * through which a wide directory stream is referenced.
  */
-typedef struct
-{
-	/* disk transfer area for this dir */
-	struct _wfinddata_t	dd_dta;
-
-	/* dirent struct to return from dir (NOTE: this makes this thread
-	 * safe as long as only one thread uses a particular DIR struct at
-	 * a time) */
-	struct _wdirent		dd_dir;
-
-	/* _findnext handle */
-	intptr_t		dd_handle;
-
-	/*
-	 * Status of search:
-	 *   0 = not started yet (next entry to read is first entry)
-	 *  -1 = off the end
-	 *   positive = 0 based index of next entry
-	 */
-	int			dd_stat;
-
-	/* given path for dir with search pattern (struct is extended) */
-	wchar_t			dd_name[1];
-} _WDIR;
+typedef struct __wdirstream_t _WDIR;
 
 _WDIR* __cdecl __MINGW_NOTHROW _wopendir (const wchar_t*);
 struct _wdirent*  __cdecl __MINGW_NOTHROW _wreaddir (_WDIR*);
diff --git a/winsup/mingw/mingwex/dirent.c b/winsup/mingw/mingwex/dirent.c
index 399a8d1b3..0d3e54a09 100644
--- a/winsup/mingw/mingwex/dirent.c
+++ b/winsup/mingw/mingwex/dirent.c
@@ -28,6 +28,60 @@
 #define SUFFIX	_T("*")
 #define	SLASH	_T("\\")
 
+struct __dirstream_t
+{
+  /* Actual (private) declaration for opaque data type "DIR". */
+
+    /* disk transfer area for this dir */
+    struct _finddata_t	dd_dta;
+
+    /* dirent struct to return from dir (NOTE: this makes this thread
+     * safe as long as only one thread uses a particular DIR struct at
+     * a time) */
+    struct dirent	dd_dir;
+
+    /* _findnext handle */
+    intptr_t		dd_handle;
+
+    /*
+     * Status of search:
+     *   (type is now int -- was short in older versions).
+     *   0 = not started yet (next entry to read is first entry)
+     *  -1 = off the end
+     *   positive = 0 based index of next entry
+     */
+    int			dd_stat;
+
+    /* given path for dir with search pattern (struct is extended) */
+    char		dd_name[1];
+};
+
+struct __wdirstream_t
+{
+  /* Actual (private) declaration for opaque data type "_WDIR". */
+
+    /* disk transfer area for this dir */
+    struct _wfinddata_t	dd_dta;
+
+    /* dirent struct to return from dir (NOTE: this makes this thread
+     * safe as long as only one thread uses a particular DIR struct at
+     * a time) */
+    struct _wdirent	dd_dir;
+
+    /* _findnext handle */
+    intptr_t		dd_handle;
+
+    /*
+     * Status of search:
+     *   0 = not started yet (next entry to read is first entry)
+     *  -1 = off the end
+     *   positive = 0 based index of next entry
+     */
+    int			dd_stat;
+
+    /* given path for dir with search pattern (struct is extended) */
+    wchar_t		dd_name[1];
+};
 
 /* Helper for opendir().  */
 static inline unsigned _tGetFileAttributes (const _TCHAR * tPath)