diff --git a/interface/wx/msgout.h b/interface/wx/msgout.h
index 250fa190e3..cd44896a15 100644
--- a/interface/wx/msgout.h
+++ b/interface/wx/msgout.h
@@ -113,6 +113,17 @@ public:
     wxMessageOutputStderr(FILE *fp = stderr);
 };
 
+/**
+    Flags used with wxMessageOutputBest.
+
+    See wxMessageOutputBest::wxMessageOutputBest().
+ */
+enum wxMessageOutputFlags
+{
+    wxMSGOUT_PREFER_STDERR = 0, ///< use stderr if available (this is the default)
+    wxMSGOUT_PREFER_MSGBOX = 1  ///< always use message box if available
+};
+
 /**
     Output messages in the best possible way.