diff --git a/src/mred/wxme/wx_mpriv.cxx b/src/mred/wxme/wx_mpriv.cxx
index 439d80d76a..aba1bc5b2f 100644
--- a/src/mred/wxme/wx_mpriv.cxx
+++ b/src/mred/wxme/wx_mpriv.cxx
@@ -44,6 +44,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <ctype.h>
+#include <math.h>
 
 #include "wx_mpriv.h"