diff --git a/src/msw/timer.cpp b/src/msw/timer.cpp
index 09f830cd95..1ebd9535cf 100644
--- a/src/msw/timer.cpp
+++ b/src/msw/timer.cpp
@@ -125,10 +125,10 @@ wxTimer::~wxTimer()
 
 bool wxTimer::Start(int milliseconds, bool oneShot)
 {
-    wxCHECK_MSG( m_milli > 0, false, wxT("invalid value for timer timeour") );
-
     (void)wxTimerBase::Start(milliseconds, oneShot);
 
+    wxCHECK_MSG( m_milli > 0, false, wxT("invalid value for timer timeour") );
+
     // find a window for SetTimer(): it should be a valid HWND owned by this
     // thread (even if we had a non NULL m_hwnd before, reset it in case the
     // owner has changed)