diff --git a/etc/taskcluster/decision_task.py b/etc/taskcluster/decision_task.py
index 99b2bc585f6a..912ed982ddfe 100644
--- a/etc/taskcluster/decision_task.py
+++ b/etc/taskcluster/decision_task.py
@@ -659,6 +659,8 @@ def wpt_chunks(platform, make_chunk_task, build_task, total_chunks, processes,
             .with_script("tar -xzf target.tar.gz")
             .with_index_and_artifacts_expire_in(log_artifacts_expire_in)
             .with_max_run_time_minutes(90)
+            .with_retry_on_exit_codes(TASKCLUSTER_RETRY_EXIT_CODE)
+            .with_max_auto_retries(1)  # This does not include the initial run
             .with_env(
                 TOTAL_CHUNKS=str(total_chunks),
                 THIS_CHUNK=str(this_chunk),
@@ -1005,5 +1007,9 @@ def magicleap_nightly():
 CONFIG.windows_worker_type = "win2016"
 CONFIG.macos_worker_type = "macos"
 
+# Must match the constant with the same name in `python/servo/testing_commands.py`
+TASKCLUSTER_RETRY_EXIT_CODE = 17
+
+
 if __name__ == "__main__":  # pragma: no cover
     main(task_for=os.environ["TASK_FOR"])
diff --git a/etc/taskcluster/decisionlib.py b/etc/taskcluster/decisionlib.py
index acd8556ad793..5fdc75493225 100644
--- a/etc/taskcluster/decisionlib.py
+++ b/etc/taskcluster/decisionlib.py
@@ -145,6 +145,7 @@ def __init__(self, name):
         self.extra = {}
         self.treeherder_required = False
         self.priority = None  # Defaults to 'lowest'
+        self.max_auto_retries = None  # Defaults to 5
 
     # All `with_*` methods return `self`, so multiple method calls can be chained.
     with_description = chaining(setattr, "description")
@@ -155,6 +156,7 @@ def __init__(self, name):
     with_expires_in = chaining(setattr, "expires_in")
     with_index_and_artifacts_expire_in = chaining(setattr, "index_and_artifacts_expire_in")
     with_priority = chaining(setattr, "priority")
+    with_max_auto_retries = chaining(setattr, "max_auto_retries")
 
     with_dependencies = chaining(append_to_attr, "dependencies")
     with_scopes = chaining(append_to_attr, "scopes")
@@ -251,6 +253,7 @@ def create(self):
             routes=routes,
             extra=self.extra,
             priority=self.priority,
+            retries=self.max_auto_retries,
         )
 
         task_id = taskcluster.slugId()
@@ -315,10 +318,12 @@ def __init__(self, *args, **kwargs):
         self.features = {}
         self.mounts = []
         self.artifacts = []
+        self.retry_on_exit_codes = []
 
     with_max_run_time_minutes = chaining(setattr, "max_run_time_minutes")
     with_mounts = chaining(append_to_attr, "mounts")
     with_env = chaining(update_attr, "env")
+    with_retry_on_exit_codes = chaining(append_to_attr, "retry_on_exit_codes")
 
     def build_command(self):  # pragma: no cover
         """
@@ -337,6 +342,9 @@ def build_worker_payload(self):
             "command": self.build_command(),
             "maxRunTime": self.max_run_time_minutes * 60
         }
+        # https://github.com/taskcluster/generic-worker/blob/a8fe0120f3/simple_posix.yml#L224-L249
+        if self.retry_on_exit_codes:
+            worker_payload["onExitStatus"] = {"retry": self.retry_on_exit_codes}
         return dict_update_if_truthy(
             worker_payload,
             env=self.env,
diff --git a/python/servo/testing_commands.py b/python/servo/testing_commands.py
index 1aa2b0961e50..ea67881d1207 100644
--- a/python/servo/testing_commands.py
+++ b/python/servo/testing_commands.py
@@ -43,6 +43,10 @@
 from servo_tidy import tidy
 from servo_tidy_tests import test_tidy
 
+
+# Must match the constant with the same name in `etc/taskcluster/decision_task.py`
+TASKCLUSTER_RETRY_EXIT_CODE = 17
+
 SCRIPT_PATH = os.path.split(__file__)[0]
 PROJECT_TOPLEVEL_PATH = os.path.abspath(os.path.join(SCRIPT_PATH, "..", ".."))
 WEB_PLATFORM_TESTS_PATH = os.path.join("tests", "wpt", "web-platform-tests")
@@ -577,7 +581,7 @@ def filter_intermittents(self, summary, log_filteredsummary, log_intermittents,
 
         if len(actual_failures) == 0:
             return 0
-        return 1
+        return TASKCLUSTER_RETRY_EXIT_CODE
 
     @Command('test-android-startup',
              description='Extremely minimal testing of Servo for Android',