diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c
index 8158508d8c..6fca8e358f 100644
--- a/src/backend/access/nbtree/nbtree.c
+++ b/src/backend/access/nbtree/nbtree.c
@@ -832,9 +832,6 @@ btvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
 		btvacuumscan(info, stats, NULL, NULL, 0);
 	}
 
-	/* Finally, vacuum the FSM */
-	IndexFreeSpaceMapVacuum(info->index);
-
 	/*
 	 * It's quite possible for us to be fooled by concurrent page splits into
 	 * double-counting some index tuples, so disbelieve any total that exceeds
@@ -976,6 +973,21 @@ btvacuumscan(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 
 	MemoryContextDelete(vstate.pagedelcontext);
 
+	/*
+	 * If we found any recyclable pages (and recorded them in the FSM), then
+	 * forcibly update the upper-level FSM pages to ensure that searchers can
+	 * find them.  It's possible that the pages were also found during
+	 * previous scans and so this is a waste of time, but it's cheap enough
+	 * relative to scanning the index that it shouldn't matter much, and
+	 * making sure that free pages are available sooner not later seems
+	 * worthwhile.
+	 *
+	 * Note that if no recyclable pages exist, we don't bother vacuuming the
+	 * FSM at all.
+	 */
+	if (vstate.totFreePages > 0)
+		IndexFreeSpaceMapVacuum(rel);
+
 	/* update statistics */
 	stats->num_pages = num_pages;
 	stats->pages_free = vstate.totFreePages;
diff --git a/src/backend/access/spgist/spgvacuum.c b/src/backend/access/spgist/spgvacuum.c
index 72839cb8f9..a83a4b581e 100644
--- a/src/backend/access/spgist/spgvacuum.c
+++ b/src/backend/access/spgist/spgvacuum.c
@@ -845,6 +845,21 @@ spgvacuumscan(spgBulkDeleteState *bds)
 	/* Propagate local lastUsedPage cache to metablock */
 	SpGistUpdateMetaPage(index);
 
+	/*
+	 * If we found any empty pages (and recorded them in the FSM), then
+	 * forcibly update the upper-level FSM pages to ensure that searchers can
+	 * find them.  It's possible that the pages were also found during
+	 * previous scans and so this is a waste of time, but it's cheap enough
+	 * relative to scanning the index that it shouldn't matter much, and
+	 * making sure that free pages are available sooner not later seems
+	 * worthwhile.
+	 *
+	 * Note that if no empty pages exist, we don't bother vacuuming the FSM at
+	 * all.
+	 */
+	if (bds->stats->pages_deleted > 0)
+		IndexFreeSpaceMapVacuum(index);
+
 	/*
 	 * Truncate index if possible
 	 *
@@ -916,7 +931,6 @@ dummy_callback(ItemPointer itemptr, void *state)
 IndexBulkDeleteResult *
 spgvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
 {
-	Relation	index = info->index;
 	spgBulkDeleteState bds;
 
 	/* No-op in ANALYZE ONLY mode */
@@ -926,8 +940,8 @@ spgvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
 	/*
 	 * We don't need to scan the index if there was a preceding bulkdelete
 	 * pass.  Otherwise, make a pass that won't delete any live tuples, but
-	 * might still accomplish useful stuff with redirect/placeholder cleanup,
-	 * and in any case will provide stats.
+	 * might still accomplish useful stuff with redirect/placeholder cleanup
+	 * and/or FSM housekeeping, and in any case will provide stats.
 	 */
 	if (stats == NULL)
 	{
@@ -940,9 +954,6 @@ spgvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
 		spgvacuumscan(&bds);
 	}
 
-	/* Finally, vacuum the FSM */
-	IndexFreeSpaceMapVacuum(index);
-
 	/*
 	 * It's quite possible for us to be fooled by concurrent tuple moves into
 	 * double-counting some index tuples, so disbelieve any total that exceeds