diff --git a/src/Main/locale.cxx b/src/Main/locale.cxx
index 41fafe995..2544d0ba7 100644
--- a/src/Main/locale.cxx
+++ b/src/Main/locale.cxx
@@ -26,6 +26,7 @@
 #include <windows.h>
 #endif
 
+#include <cstdarg> // for va_start/_end
 #include <boost/foreach.hpp>
 
 #include <simgear/props/props_io.hxx>