diff --git a/x11/xdtm/patches/patch-lexical_l b/x11/xdtm/patches/patch-lexical_l
new file mode 100644
index 00000000000..c17b78fceb6
--- /dev/null
+++ b/x11/xdtm/patches/patch-lexical_l
@@ -0,0 +1,22 @@
+$OpenBSD: patch-lexical_l,v 1.1 2009/10/16 10:30:02 sthen Exp $
+--- lexical.l.orig	Fri Oct 16 10:15:02 2009
++++ lexical.l	Fri Oct 16 10:16:10 2009
+@@ -1,3 +1,4 @@
++%option yylineno
+ %{ /*-*- Mode: C -*-*/
+ /**************************************************************************
+  ** File     :       lexical.l                                           **
+@@ -171,13 +172,6 @@ static int numkeywords = (sizeof(keywordtable)/sizeof(
+ 
+ int parseerror=0;                   /* Number of parse errors */
+ char errormessage[255];             /* used for error messsages */
+-
+-/*
+- * ``yylineno'' not POSIX standard, so have to simulate it when using flex.
+- */
+-#ifdef FLEX_SCANNER
+-int yylineno=0;
+-#endif
+ 
+ %}
+ %%