diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index f65691d7b0..9ff18c6542 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2017-09-27  Tom Tromey  <tom@tromey.com>
+
+	* cli/cli-script.c (user_defined_command): Constify.
+
 2017-09-27  Tom Tromey  <tom@tromey.com>
 
 	* cli/cli-dump.c (dump_memory_command, dump_value_command)
diff --git a/gdb/cli/cli-script.c b/gdb/cli/cli-script.c
index 37466fd766..0a93e8b54f 100644
--- a/gdb/cli/cli-script.c
+++ b/gdb/cli/cli-script.c
@@ -1401,7 +1401,7 @@ validate_comname (char **comname)
 
 /* This is just a placeholder in the command data structures.  */
 static void
-user_defined_command (char *ignore, int from_tty)
+user_defined_command (const char *ignore, int from_tty)
 {
 }