diff --git a/taskcluster/gecko_taskgraph/decision.py b/taskcluster/gecko_taskgraph/decision.py
index 71a8e1ddaf30..d38483611cc3 100644
--- a/taskcluster/gecko_taskgraph/decision.py
+++ b/taskcluster/gecko_taskgraph/decision.py
@@ -7,6 +7,7 @@ import os
 import json
 import logging
 import time
+import shutil
 import sys
 from collections import defaultdict
 
@@ -251,6 +252,15 @@ def taskgraph_decision(options, parameters=None):
     if len(push_schedules) > 0:
         write_artifact("bugbug-push-schedules.json", push_schedules.popitem()[1])
 
+    # cache run-task & misc/fetch-content
+    scripts_root_dir = os.path.join(
+        "/builds/worker/checkouts/gecko/taskcluster/scripts"
+    )
+    run_task_file_path = os.path.join(scripts_root_dir, "run-task")
+    fetch_content_file_path = os.path.join(scripts_root_dir, "misc/fetch-content")
+    shutil.copy2(run_task_file_path, ARTIFACTS_DIR)
+    shutil.copy2(fetch_content_file_path, ARTIFACTS_DIR)
+
     # actually create the graph
     create_tasks(
         tgg.graph_config,
diff --git a/taskcluster/gecko_taskgraph/test/test_transforms_job.py b/taskcluster/gecko_taskgraph/test/test_transforms_job.py
index 44f2a6a9e179..43d9c18d3667 100644
--- a/taskcluster/gecko_taskgraph/test/test_transforms_job.py
+++ b/taskcluster/gecko_taskgraph/test/test_transforms_job.py
@@ -60,6 +60,8 @@ def transform(monkeypatch, config):
     This gives test functions an easy way to generate the inputs required for
     many of the `run_using` subsystems.
     """
+    # Needed by 'generic_worker_run_task'
+    monkeypatch.setenv("TASK_ID", "fakeid")
 
     def inner(task_input):
         task = deepcopy(TASK_DEFAULTS)
diff --git a/taskcluster/gecko_taskgraph/transforms/job/run_task.py b/taskcluster/gecko_taskgraph/transforms/job/run_task.py
index c2391d3d4dcd..759bf2c66f4f 100644
--- a/taskcluster/gecko_taskgraph/transforms/job/run_task.py
+++ b/taskcluster/gecko_taskgraph/transforms/job/run_task.py
@@ -6,6 +6,8 @@ Support for running jobs that are invoked via the `run-task` script.
 """
 
 
+import os
+
 from mozpack import path
 
 from gecko_taskgraph.transforms.task import taskref_or_string
@@ -91,9 +93,11 @@ worker_defaults = {
 
 
 def script_url(config, script):
-    return config.params.file_url(
-        f"taskcluster/scripts/{script}",
-    )
+    if "TASK_ID" not in os.environ:
+        raise Exception("TASK_ID must be defined to use run-task on generic-worker")
+    task_id = os.environ["TASK_ID"]
+    tc_url = "http://firefox-ci-tc.services.mozilla.com"
+    return f"{tc_url}/api/queue/v1/task/{task_id}/artifacts/public/{script}"
 
 
 @run_job_using(
@@ -198,7 +202,7 @@ def generic_worker_run_task(config, job, taskdesc):
         worker["mounts"].append(
             {
                 "content": {
-                    "url": script_url(config, "misc/fetch-content"),
+                    "url": script_url(config, "fetch-content"),
                 },
                 "file": "./fetch-content",
             }