diff --git a/src/msw/joystick.cpp b/src/msw/joystick.cpp
index f9b7bc15c5..2cec62c58b 100644
--- a/src/msw/joystick.cpp
+++ b/src/msw/joystick.cpp
@@ -157,6 +157,7 @@ wxJoystick::wxJoystick(int joystick)
     JOYINFO joyInfo;
     int i, maxsticks;
 
+    m_thread = NULL;
     maxsticks = joyGetNumDevs();
     for( i=0; i<maxsticks; i++ )
     {