diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 7008541f2e5..6f07d5e8ee0 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2017-09-27  Tom Tromey  <tom@tromey.com>
+
+	* dtrace-probe.c (info_probes_dtrace_command): Constify.
+
 2017-09-27  Tom Tromey  <tom@tromey.com>
 
 	* command.h (not_just_help_class_command): Update.
diff --git a/gdb/dtrace-probe.c b/gdb/dtrace-probe.c
index 5a4daa3c6be..2bbe03e4b30 100644
--- a/gdb/dtrace-probe.c
+++ b/gdb/dtrace-probe.c
@@ -904,7 +904,7 @@ const struct probe_ops dtrace_probe_ops =
 /* Implementation of the `info probes dtrace' command.  */
 
 static void
-info_probes_dtrace_command (char *arg, int from_tty)
+info_probes_dtrace_command (const char *arg, int from_tty)
 {
   info_probes_for_ops (arg, from_tty, &dtrace_probe_ops);
 }