diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 19eecab..4e46ddb 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -2707,6 +2707,7 @@ MarkBufferDirtyHint(Buffer buffer, bool buffer_std)
 		if (dirtied)
 		{
 			VacuumPageDirty++;
+			pgBufferUsage.shared_blks_dirtied++;
 			if (VacuumCostActive)
 				VacuumCostBalance += VacuumCostPageDirty;
 		}