diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 4cc0cb8794f..d8992d48106 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2021-05-19  John Baldwin  <jhb@FreeBSD.org>
+
+	* dwarf2/read.c (tu_abbrev_offset::operator<): Mark const.
+
 2021-05-17  Tom Tromey  <tom@tromey.com>
 
 	* dwarf2/read.h: Update include.
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 8a57aeee61c..2cd8a95658a 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -7116,7 +7116,7 @@ struct tu_abbrev_offset
   {}
 
   /* This is used when sorting.  */
-  bool operator< (const tu_abbrev_offset &other)
+  bool operator< (const tu_abbrev_offset &other) const
   {
     return abbrev_offset < other.abbrev_offset;
   }