diff --git a/include/wx/defs.h b/include/wx/defs.h
index 96ca1b6d9f..f1e13037b6 100644
--- a/include/wx/defs.h
+++ b/include/wx/defs.h
@@ -269,6 +269,8 @@ typedef int wxWindowID;
         #define HAVE_EXPLICIT
     #elif defined(__DIGITALMARS__)
         #define HAVE_EXPLICIT
+    #elif defined(__WATCOMC__)
+        #define HAVE_EXPLICIT
     #endif
 #endif /*  !HAVE_EXPLICIT */