1 files changed, 1 insertions, 1 deletions

diff --git a/lib-src/sorted-doc.c b/lib-src/sorted-doc.c
index db3f3029532..4fe830e4013 100644
--- a/lib-src/sorted-doc.c
+++ b/lib-src/sorted-doc.c
@@ -93,7 +93,7 @@ xmalloc (int size)
 }
 
 char *
-xstrdup (char *str)
+xstrdup (const char *str)
 {
   char *buf = xmalloc (strlen (str) + 1);
   (void) strcpy (buf, str);