diff --git a/builtin/fsck.c b/builtin/fsck.c
index fa101e0db2..c11cb2a95f 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -984,10 +984,24 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 	}
 
 	if (keep_cache_objects) {
+		struct worktree **worktrees, **p;
+
 		verify_index_checksum = 1;
 		verify_ce_order = 1;
-		repo_read_index(the_repository);
-		fsck_index(the_repository->index);
+
+		worktrees = get_worktrees();
+		for (p = worktrees; *p; p++) {
+			struct worktree *wt = *p;
+			struct index_state istate =
+				INDEX_STATE_INIT(the_repository);
+
+			if (read_index_from(&istate,
+					    worktree_git_path(wt, "index"),
+					    get_worktree_git_dir(wt)) > 0)
+				fsck_index(&istate);
+			discard_index(&istate);
+		}
+		free_worktrees(worktrees);
 	}
 
 	check_connectivity();
diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index de0f6d5e7f..e01a519a69 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -1023,4 +1023,16 @@ test_expect_success 'fsck error on gitattributes with excessive size' '
 	test_cmp expected actual
 '
 
+test_expect_success 'fsck detects problems in worktree index' '
+	test_when_finished "git worktree remove -f wt" &&
+	git worktree add wt &&
+
+	echo "this will be removed to break the worktree index" >wt/file &&
+	git -C wt add file &&
+	blob=$(git -C wt rev-parse :file) &&
+	remove_object $blob &&
+
+	test_must_fail git fsck
+'
+
 test_done