diff --git a/.github/workflows/run-unit-tests.yml b/.github/workflows/run-unit-tests.yml
index e7d3cb022..e5b6779c4 100644
--- a/.github/workflows/run-unit-tests.yml
+++ b/.github/workflows/run-unit-tests.yml
@@ -118,14 +118,18 @@ jobs:
           python3 -B test/test_ed25519_compact_field.py -v
           python3 -B test/test_ed25519_compact.py -v
 
-      - name: Compile ordinary STM32 USB Companion with pinned core and RadioLib
-        run: pio run -e RAK_3x72_companion_radio_usb
-
-      - name: Qualify Wio-E5 Mini Companion at release version length
-        run: >-
-          bash build.sh build-firmware wio-e5-mini_companion_radio_usb
-          --firmware-version v1.17.1.9-halo-keymind-cascade-dev
-          --radio-preset usa-cascade-fixed --profile cascade --require-ota
+      - name: Qualify all small STM32 USB Companions at release version length
+        run: |
+          set -euo pipefail
+          for target in \
+            RAK_3x72_companion_radio_usb \
+            wio-e5-mini_companion_radio_usb \
+            wio-e5_companion_radio_usb \
+            Tiny_Relay_companion_radio_usb; do
+            bash build.sh build-firmware "$target" \
+              --firmware-version v1.18.0.1-halo-keymind-cascade-dev \
+              --radio-preset usa-cascade-fixed --profile cascade --require-ota
+          done
 
   bootloader-version:
     runs-on: ubuntu-latest
diff --git a/test/test_stm32_companion_profile.py b/test/test_stm32_companion_profile.py
index d2b2b11b1..b8f32ba96 100644
--- a/test/test_stm32_companion_profile.py
+++ b/test/test_stm32_companion_profile.py
@@ -8,6 +8,9 @@ fixing its size limit by silently shrinking storage or Companion capacities.
 import configparser
 from pathlib import Path
 import re
+import shlex
+import subprocess
+import textwrap
 import unittest
 
 
@@ -98,5 +101,25 @@ class WioSTM32CompanionProfileTest(STM32CompanionProfileTest):
                          r"-D\s+PIN_USER_BTN=USER_BTN\b")
 
 
+class STM32CompanionCICoverageTest(unittest.TestCase):
+    def test_every_small_companion_is_linked_serially_at_release_version_length(self):
+        workflow = (ROOT / ".github/workflows/run-unit-tests.yml").read_text()
+        job = re.search(r"^  stm32-companion-smoke:\n(.*?)(?=^  [\w-]+:|\Z)",
+                        workflow, re.MULTILINE | re.DOTALL)
+        self.assertIsNotNone(job)
+        script = job[1].replace("\\\n", "")
+        loop = re.search(r"for target in (.*?); do", script, re.DOTALL)
+        self.assertIsNotNone(loop)
+        self.assertEqual(set(shlex.split(loop[1])), {
+            "RAK_3x72_companion_radio_usb", "wio-e5-mini_companion_radio_usb",
+            "wio-e5_companion_radio_usb", "Tiny_Relay_companion_radio_usb"})
+        self.assertIn("set -euo pipefail", script)
+        self.assertIn('bash build.sh build-firmware "$target"', script)
+        self.assertIn("--firmware-version v1.18.0.1-halo-keymind-cascade-dev", script)
+        self.assertNotIn(" &", script)
+        command = textwrap.dedent(job[1].rsplit("        run: |\n", 1)[1])
+        subprocess.run(["bash", "-n"], input=command, text=True, check=True)
+
+
 if __name__ == "__main__":
     unittest.main()