diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index af22deb2c6c..25ae470bb93 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2017-10-14  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* nat/linux-osdata.c (struct pid_pgid_entry) <operator<>: Make
+	const.
+
 2017-10-14  Simon Marchi  <simon.marchi@polymtl.ca>
 
 	* target.h: Include tracepoint.h.
diff --git a/gdb/nat/linux-osdata.c b/gdb/nat/linux-osdata.c
index 5d1a7bd6ddb..0980c8d0176 100644
--- a/gdb/nat/linux-osdata.c
+++ b/gdb/nat/linux-osdata.c
@@ -407,7 +407,7 @@ struct pid_pgid_entry
     return pid == pgid;
   }
 
-  bool operator< (const pid_pgid_entry &other)
+  bool operator< (const pid_pgid_entry &other) const
   {
     /* Sort by PGID.  */
     if (this->pgid != other.pgid)