diff --git a/gdb/dwarf2/cooked-index-entry.c b/gdb/dwarf2/cooked-index-entry.c
index 9a921f22c21..560d6952206 100644
--- a/gdb/dwarf2/cooked-index-entry.c
+++ b/gdb/dwarf2/cooked-index-entry.c
@@ -33,6 +33,7 @@ to_string (cooked_index_flag flags)
     MAP_ENUM_FLAG (IS_LINKAGE),
     MAP_ENUM_FLAG (IS_TYPE_DECLARATION),
     MAP_ENUM_FLAG (IS_PARENT_DEFERRED),
+    MAP_ENUM_FLAG (IS_SYNTHESIZED),
   };
 
   return flags.to_string (mapping);