diff --git a/R/outpack_index.R b/R/outpack_index.R
index 1308ae34..f17d91ac 100644
--- a/R/outpack_index.R
+++ b/R/outpack_index.R
@@ -74,7 +74,7 @@ index_update <- function(root_path, prev, skip_cache, progress) {
 
   if (!identical(data, prev)) {
     fs::dir_create(dirname(path_index))
-    saverds_atomic(data, path_index)
+    saverds_atomic(data, path_index, allow_fail = TRUE)
   }
 
   data
diff --git a/R/util.R b/R/util.R
index a28922f6..0c9bdcdc 100644
--- a/R/util.R
+++ b/R/util.R
@@ -617,10 +617,18 @@ file_canonical_case <- function(path, workdir) {
 }
 
 
-saverds_atomic <- function(data, path) {
+saverds_atomic <- function(data, path, allow_fail = FALSE) {
   tmp <- tempfile(pattern = sub("\\.rds", "", basename(path)),
                   tmpdir = dirname(path),
                   fileext = ".rds")
   saveRDS(data, tmp)
-  fs::file_move(tmp, path)
+  if (allow_fail) {
+    tryCatch(
+      fs::file_move(tmp, path),
+      error = function(e) unlink(tmp))
+  } else {
+    tryCatch(
+      fs::file_move(tmp, path),
+      finally = unlink(tmp))
+  }
 }
diff --git a/tests/testthat/test-util.R b/tests/testthat/test-util.R
index 3ea032e8..f06bc747 100644
--- a/tests/testthat/test-util.R
+++ b/tests/testthat/test-util.R
@@ -306,3 +306,18 @@ test_that("can convert files to canonical case", {
   expect_equal(file_canonical_case("A/win~1/C", tmp), NA_character_)
   expect_equal(file_canonical_case(c("a/b/c", "a/b/d"), tmp), c("a/b/c", NA))
 })
+
+
+test_that("can gracefully cope with rds save failure", {
+  mock_move <- mockery::mock(stop("some error"), cycle = TRUE)
+  mockery::stub(saverds_atomic, "fs::file_move", mock_move)
+  tmp <- withr::local_tempdir()
+  path <- file.path(tmp, "file.rds")
+  expect_silent(
+    saverds_atomic(NULL, path, allow_fail = TRUE))
+  expect_equal(dir(tmp), character())
+  expect_error(
+    saverds_atomic(NULL, path, allow_fail = FALSE),
+    "some error")
+  expect_equal(dir(tmp), character())
+})