diff --git a/winsup/cygwin/posix_timer.cc b/winsup/cygwin/posix_timer.cc
index a140b00e9..c0d548fe9 100644
--- a/winsup/cygwin/posix_timer.cc
+++ b/winsup/cygwin/posix_timer.cc
@@ -31,7 +31,9 @@ timer_tracker::cancel ()
   SetEvent (cancel_evt);
   if (sync_thr)
     {
+      ReleaseSRWLockExclusive (&srwlock);
       res = WaitForSingleObject (sync_thr, INFINITE);
+      AcquireSRWLockExclusive (&srwlock);
       if (res != WAIT_OBJECT_0)
 	debug_printf ("WFSO returned unexpected value %u, %E", res);
     }
diff --git a/winsup/cygwin/release/3.0.3 b/winsup/cygwin/release/3.0.3
index 66ae63943..b8c89cbe9 100644
--- a/winsup/cygwin/release/3.0.3
+++ b/winsup/cygwin/release/3.0.3
@@ -11,3 +11,6 @@ Bug Fixes
 
 - Fix a resource leak in posix timers.
   Addresses: https://cygwin.com/ml/cygwin/2019-03/msg00120.html
+
+- Fix a deadlock in posix timers
+  Addresses: https://cygwin.com/ml/cygwin/2019-03/msg00158.html