diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 9cc060e6d96..b94384b2829 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2017-12-30  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* dwarf2read.c (struct mapped_debug_names): Make final.
+	(struct mapped_index): Make final.
+
 2017-12-29  Simon Marchi  <simon.marchi@ericsson.com>
 
 	* common/diagnostics.h
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 484cbcee186..85e33f0f9dd 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -277,7 +277,7 @@ protected:
 
 /* A description of the mapped index.  The file format is described in
    a comment by the code that writes the index.  */
-struct mapped_index : public mapped_index_base
+struct mapped_index final : public mapped_index_base
 {
   /* A slot/bucket in the symbol table hash.  */
   struct symbol_table_slot
@@ -318,7 +318,7 @@ struct mapped_index : public mapped_index_base
 
 /* A description of the mapped .debug_names.
    Uninitialized map has CU_COUNT 0.  */
-struct mapped_debug_names : public mapped_index_base
+struct mapped_debug_names final : public mapped_index_base
 {
   bfd_endian dwarf5_byte_order;
   bool dwarf5_is_dwarf64;