diff --git a/sql/ha_blackhole.cc b/sql/ha_blackhole.cc
index b8ae92e3d10..9ac4ba2da15 100644
--- a/sql/ha_blackhole.cc
+++ b/sql/ha_blackhole.cc
@@ -126,6 +126,7 @@ int ha_blackhole::external_lock(THD *thd, int lock_type)
 
 uint ha_blackhole::lock_count(void) const
 {
+  DBUG_ENTER("ha_blackhole::lock_count");
   DBUG_RETURN(0);
 }
 
@@ -133,6 +134,7 @@ THR_LOCK_DATA **ha_blackhole::store_lock(THD *thd,
                                          THR_LOCK_DATA **to,
                                          enum thr_lock_type lock_type)
 {
+  DBUG_ENTER("ha_blackhole::store_lock");
   DBUG_RETURN(to);
 }