diff --git a/gdb/cp-name-parser.y b/gdb/cp-name-parser.y
index 34c691ddabb..21ba51679d3 100644
--- a/gdb/cp-name-parser.y
+++ b/gdb/cp-name-parser.y
@@ -248,6 +248,10 @@ cpname_state::make_name (const char *name, int len)
 
 static int yylex (YYSTYPE *, cpname_state *);
 static void yyerror (cpname_state *, const char *);
+
+#include "diagnostics.h"
+DIAGNOSTIC_IGNORE_UNUSED_BUT_SET_VARIABLE
+
 %}
 
 %type <comp> exp exp1 type start start_opt oper colon_name