diff --git a/ChangeLog b/ChangeLog
index e4fd9baa81a5b0d9b171ef9ff2eafb483a9c11ce..3bf584ba43df63fbac35f70bd29574fca0404d92 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,9 @@ CVS code -
 	  atom in the default regex string for quotestr, according to
 	  ASCII.  Changes to main(), nano.1, nanorc.5, and
 	  nanorc.sample. (DLR)
+- chars.c:
+  mbstrchr()
+	- Make parameter c const. (DLR)
 - winio.c:
   edit_scroll()
 	- Redraw the lines before and after the scrolled region even if
diff --git a/src/chars.c b/src/chars.c
index 1331fffdf4394cd8d484d325fe7a54abba3cfab3..05041bc4a4d5a7d4e1d892c1d71f1763ec5eb39b 100644
--- a/src/chars.c
+++ b/src/chars.c
@@ -3,7 +3,7 @@
  *   chars.c                                                              *
  *                                                                        *
  *   Copyright (C) 2001-2004 Chris Allegretta                             *
- *   Copyright (C) 2005 David Lawrence Ramsey                             *
+ *   Copyright (C) 2005-2006 David Lawrence Ramsey                        *
  *   This program is free software; you can redistribute it and/or modify *
  *   it under the terms of the GNU General Public License as published by *
  *   the Free Software Foundation; either version 2, or (at your option)  *
@@ -835,7 +835,7 @@ char *revstrpbrk(const char *s, const char *accept, const char
 
 #ifndef DISABLE_JUSTIFY
 /* This function is equivalent to strchr() for multibyte strings. */
-char *mbstrchr(const char *s, char *c)
+char *mbstrchr(const char *s, const char *c)
 {
     assert(s != NULL && c != NULL);
 
diff --git a/src/proto.h b/src/proto.h
index c6ed56929d48ef7264c65eb21f6f7d74cdb30fd4..f0ab86d0d731c3182cedacc2e57dc1c5d0c229f9 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -3,7 +3,7 @@
  *   proto.h                                                              *
  *                                                                        *
  *   Copyright (C) 1999-2004 Chris Allegretta                             *
- *   Copyright (C) 2005 David Lawrence Ramsey                             *
+ *   Copyright (C) 2005-2006 David Lawrence Ramsey                        *
  *   This program is free software; you can redistribute it and/or modify *
  *   it under the terms of the GNU General Public License as published by *
  *   the Free Software Foundation; either version 2, or (at your option)  *
@@ -201,7 +201,7 @@ char *revstrpbrk(const char *s, const char *accept, const char
 	*rev_start);
 #endif
 #ifndef DISABLE_JUSTIFY
-char *mbstrchr(const char *s, char *c);
+char *mbstrchr(const char *s, const char *c);
 #ifdef ENABLE_NANORC
 bool has_blank_chars(const char *s);
 bool has_blank_mbchars(const char *s);