diff --git a/include/wx/expr.h b/include/wx/expr.h
index 0b25cddace..e964fd4e8c 100644
--- a/include/wx/expr.h
+++ b/include/wx/expr.h
@@ -80,7 +80,7 @@
 #define yy_flex_debug PROIO_flex_debug
 #define yy_flush_buffer PROIO_flush_buffer
 #if !defined(__VISAGECPP__)
-// multiply defined???
+/* multiply defined??? */
 #define yyleng PROIO_yyleng
 #define yytext PROIO_yytext
 #endif