diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index d7266b16f..6aa24f856 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,15 @@
+2014-07-14  Yaakov Selkowitz  <yselkowitz@cygwin.com>
+
+	* thread.cc (pthread_mutex::pthread_mutex): Change default type
+	to PTHREAD_MUTEX_NORMAL.
+	(pthread_mutex::unlock): Return EPERM if the mutex has no owner and
+	the mutex type is PTHREAD_MUTEX_ERRORCHECK, as on Linux.
+	(pthread_mutexattr::pthread_mutexattr): Ditto.
+	(pthread_mutex_unlock): Do not fail if mutex is a normal mutex
+	initializer.
+	* include/pthread.h (PTHREAD_MUTEX_INITIALIZER): Redefine as
+	PTHREAD_NORMAL_MUTEX_INITIALIZER_NP.
+
 2014-07-09  Corinna Vinschen  <corinna@vinschen.de>
 
 	* thread.cc (pthread::create): Use PTHREAD_DEFAULT_STACKSIZE stacksize
diff --git a/winsup/cygwin/include/pthread.h b/winsup/cygwin/include/pthread.h
index c6798f13a..bfedf1f75 100644
--- a/winsup/cygwin/include/pthread.h
+++ b/winsup/cygwin/include/pthread.h
@@ -49,7 +49,7 @@ extern "C"
 #define PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP (pthread_mutex_t)18
 #define PTHREAD_NORMAL_MUTEX_INITIALIZER_NP (pthread_mutex_t)19
 #define PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP (pthread_mutex_t)20
-#define PTHREAD_MUTEX_INITIALIZER PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP
+#define PTHREAD_MUTEX_INITIALIZER PTHREAD_NORMAL_MUTEX_INITIALIZER_NP
 #define PTHREAD_ONCE_INIT { PTHREAD_MUTEX_INITIALIZER, 0 }
 #if defined(_POSIX_THREAD_PRIO_INHERIT) && _POSIX_THREAD_PRIO_INHERIT >= 0
 #define PTHREAD_PRIO_NONE 0
diff --git a/winsup/cygwin/thread.cc b/winsup/cygwin/thread.cc
index 0a167fa4d..8fdbf3610 100644
--- a/winsup/cygwin/thread.cc
+++ b/winsup/cygwin/thread.cc
@@ -1709,7 +1709,7 @@ pthread_mutex::pthread_mutex (pthread_mutexattr *attr) :
   tid (0),
 #endif
   recursion_counter (0), condwaits (0),
-  type (PTHREAD_MUTEX_ERRORCHECK),
+  type (PTHREAD_MUTEX_NORMAL),
   pshared (PTHREAD_PROCESS_PRIVATE)
 {
   win32_obj_id = ::CreateEvent (&sec_none_nih, false, false, NULL);
@@ -1777,7 +1777,7 @@ pthread_mutex::unlock ()
   if (type == PTHREAD_MUTEX_NORMAL)
     /* no error checking */;
   else if (no_owner ())
-    res = type == PTHREAD_MUTEX_ERRORCHECK ? EINVAL : 0;
+    res = type == PTHREAD_MUTEX_ERRORCHECK ? EPERM : 0;
   else if (!pthread::equal (owner, self))
     res = EPERM;
   if (!res && recursion_counter > 0 && --recursion_counter == 0)
@@ -1851,7 +1851,7 @@ pthread_mutex::_fixup_after_fork ()
 }
 
 pthread_mutexattr::pthread_mutexattr ():verifyable_object (PTHREAD_MUTEXATTR_MAGIC),
-pshared (PTHREAD_PROCESS_PRIVATE), mutextype (PTHREAD_MUTEX_ERRORCHECK)
+pshared (PTHREAD_PROCESS_PRIVATE), mutextype (PTHREAD_MUTEX_NORMAL)
 {
 }
 
@@ -3159,7 +3159,7 @@ extern "C" int
 pthread_mutex_unlock (pthread_mutex_t *mutex)
 {
   if (pthread_mutex::is_initializer (mutex))
-    return EPERM;
+    pthread_mutex::init (mutex, NULL, *mutex);
   if (!pthread_mutex::is_good_object (mutex))
     return EINVAL;
   return (*mutex)->unlock ();