diff --git a/lib/functions.bash b/lib/functions.bash
index 7801348..2101856 100755
--- a/lib/functions.bash
+++ b/lib/functions.bash
@@ -96,12 +96,14 @@ function s3Exists {
 function s3Upload {
   local s3_path
   local localPaths
+  local tempFile
   s3_path=$(s3Path "$1")
   # shellcheck disable=SC2206
   localPaths=($2)
+  tempFile=$(makeTempFile)
   set +e
   # shellcheck disable=SC2068
-  if ! (tar --ignore-failed-read -cz ${localPaths[@]} | aws "${aws_cli_args[@]}" s3 cp - "$s3_path"); then
+  if ! (tar -czf "$tempFile" ${localPaths[@]} && aws "${aws_cli_args[@]}" s3 cp "$tempFile" "$s3_path" --quiet); then
     echo "false"
   else
     echo "true"
diff --git a/tests/functions.bats b/tests/functions.bats
index feb911f..455b29f 100644
--- a/tests/functions.bats
+++ b/tests/functions.bats
@@ -324,4 +324,24 @@ setup() {
   export BUILDKITE_PLUGIN_S3_CACHE_PIPELINE_NAME="another-pipeline"
   run -0 s3ObjectKey file
   assert_output "my-org/another-pipeline/file.tar.gz"
+  unset BUILDKITE_PLUGIN_S3_CACHE_PIPELINE_NAME
+}
+
+@test "s3Upload with existing and non-existing paths" {
+  makeTempFile() { echo /tmp/file.tar.gz; }
+  export -f makeTempFile
+  stub aws \
+    "s3 cp /tmp/file.tar.gz s3://bucket/my-org/my-pipeline/s3_path.tar.gz --quiet : :"
+  stub tar \
+    "-czf /tmp/file.tar.gz local_paths : :" \
+    "-czf /tmp/file.tar.gz local_paths : exit 1"
+
+  run -0 s3Upload s3_path local_paths
+  assert_output "true"
+  run -0 s3Upload s3_path local_paths
+  assert_output "false"
+
+  unset makeTempFile
+  unstub aws
+  unstub tar
 }
diff --git a/tests/post-command.bats b/tests/post-command.bats
index fe3d5ab..c0f49e3 100755
--- a/tests/post-command.bats
+++ b/tests/post-command.bats
@@ -11,6 +11,7 @@ function cleanup {
 trap cleanup EXIT
 
 setup() {
+  bats_require_minimum_version 1.5.0
   export BUILDKITE_BUILD_CHECKOUT_PATH=$tmp_dir
   export BUILDKITE_BUILD_ID=1
   export BUILDKITE_JOB_ID=0
@@ -21,6 +22,5 @@ setup() {
 
 @test "Post-command succeeds" {
   export BUILDKITE_PLUGIN_S3_CACHE_SAVE_0_KEY=v1-node-modules
-  run "$post_command_hook"
-  assert_success
+  run -0 "$post_command_hook"
 }
diff --git a/tests/pre-command.bats b/tests/pre-command.bats
index fae7b0e..6057d78 100644
--- a/tests/pre-command.bats
+++ b/tests/pre-command.bats
@@ -11,6 +11,7 @@ function cleanup {
 trap cleanup EXIT
 
 setup() {
+  bats_require_minimum_version 1.5.0
   export BUILDKITE_BUILD_CHECKOUT_PATH=$tmp_dir
   export BUILDKITE_BUILD_ID=1
   export BUILDKITE_JOB_ID=0
@@ -35,7 +36,6 @@ function teardown() {
 
   run "$pre_command_hook"
 
-  assert_success
   assert_output --partial "Successfully restored v1-cache-key"
 }
 
@@ -50,9 +50,8 @@ function teardown() {
     "-xz : echo true" \
     "-xz : echo true"
 
-  run "$pre_command_hook"
+  run -0 "$pre_command_hook"
 
-  assert_success
   assert_output --partial "Failed to restore cache-key-missing"
   assert_output --partial "Successfully restored cache-key-exists"
 }