diff --git a/src/msw/gauge95.cpp b/src/msw/gauge95.cpp
index 9e16993a83..f0e0bc8932 100644
--- a/src/msw/gauge95.cpp
+++ b/src/msw/gauge95.cpp
@@ -68,9 +68,18 @@ bool wxGauge95::Create(wxWindow *parent, wxWindowID id,
   int height = size.y;
 
   long msFlags = WS_CHILD | WS_VISIBLE | WS_TABSTOP;
+
+#ifndef PBS_VERTICAL
+#define PBS_VERTICAL 0x04
+#endif
+
   if (m_windowStyle & wxGA_VERTICAL)
     msFlags |= PBS_VERTICAL;
 
+#ifndef PBS_SMOOTH
+#define PBS_SMOOTH 0x01
+#endif
+
   if (m_windowStyle & wxGA_SMOOTH)
     msFlags |= PBS_SMOOTH;