===================================================================
RCS file: /cvs/mandoc/mdoc.c,v
retrieving revision 1.103
retrieving revision 1.104
diff -u -p -r1.103 -r1.104
--- mandoc/mdoc.c	2009/08/20 11:44:47	1.103
+++ mandoc/mdoc.c	2009/08/22 08:56:16	1.104
@@ -1,4 +1,4 @@
-/*	$Id: mdoc.c,v 1.103 2009/08/20 11:44:47 kristaps Exp $ */
+/*	$Id: mdoc.c,v 1.104 2009/08/22 08:56:16 kristaps Exp $ */
 /*
  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
  *
@@ -709,6 +709,12 @@ parsemacro(struct mdoc *m, int ln, char *buf)
 			break;
 		else if (' ' == buf[i])
 			break;
+
+		/* Check for invalid characters. */
+
+		if (isgraph((u_char)buf[i]))
+			continue;
+		return(mdoc_perr(m, ln, i, EPRINT));
 	}
 
 	mac[j] = 0;