diff --git a/requirements/base.in b/requirements/base.in
index c837f934..fff5c848 100644
--- a/requirements/base.in
+++ b/requirements/base.in
@@ -1,4 +1,4 @@
-tc-admin>=3.3.1
+tc-admin>=4.0.2
 taskcluster
 attrs  # http://www.attrs.org/en/stable/backward-compatibility.html
 mozilla-repo-urls
diff --git a/requirements/base.txt b/requirements/base.txt
index 9b63f64c..7cc88797 100644
--- a/requirements/base.txt
+++ b/requirements/base.txt
@@ -1,4 +1,4 @@
-# SHA1:9439d42fa1b173594e393bc7a143ac26cffe5ad6
+# SHA1:5428978ea2dc6dc1c4142793053ba03fa77517ad
 #
 # This file is autogenerated by pip-compile-multi
 # To update, run:
diff --git a/taskcluster/fxci_config_taskgraph/optimizations.py b/taskcluster/fxci_config_taskgraph/optimizations.py
index e06947fb..e9c4b2eb 100644
--- a/taskcluster/fxci_config_taskgraph/optimizations.py
+++ b/taskcluster/fxci_config_taskgraph/optimizations.py
@@ -29,9 +29,12 @@ def _get_modified_worker_pools(self) -> set[str]:
         ]
         env = os.environ.copy()
         if "TASKCLUSTER_PROXY_URL" in env:
+            # Force tc-admin diff to look at fxci even when we're running on stage
             del env["TASKCLUSTER_PROXY_URL"]
         env["TASKCLUSTER_ROOT_URL"] = FIREFOXCI_ROOT_URL
         proc = subprocess.run(cmd, stdout=subprocess.PIPE, text=True, env=env)
+        if proc.returncode not in (0, 2):
+            proc.check_returncode()
         lines = [line for line in proc.stdout.splitlines() if line.startswith("!")]
 
         worker_pools = set()