diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 14fb1d6..224bcfa 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -8,6 +8,7 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+    timeout-minutes: 10
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 2bba038..0b02ad2 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -8,13 +8,14 @@ on:
 jobs:
   ruff:
     runs-on: ubuntu-latest
+    timeout-minutes: 5
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
           python-version: "3.11"
           cache: pip
-      - name: Install dependencies
-        run: pip install -e ".[dev]"
+      - name: Install ruff
+        run: pip install ruff
       - name: Run ruff
         run: ruff check .
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 8f7119f..e828a54 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -8,6 +8,7 @@ on:
 jobs:
   pytest:
     runs-on: ubuntu-latest
+    timeout-minutes: 15
     strategy:
       matrix:
         python-version: ["3.11", "3.12"]
@@ -21,5 +22,6 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           python -m pip install -e ".[dev]"
+          python -m pip install pytest-timeout
       - name: Run pytest
-        run: pytest -v
+        run: pytest -v --timeout=30
diff --git a/EvoScientist/channels/middleware.py b/EvoScientist/channels/middleware.py
index 4daee42..f56877d 100644
--- a/EvoScientist/channels/middleware.py
+++ b/EvoScientist/channels/middleware.py
@@ -31,13 +31,18 @@ _logger = logging.getLogger(__name__)
 async def _cancel_task(task: asyncio.Task) -> None:
     """Cancel an asyncio task and await its completion.
 
-    Suppresses ``CancelledError`` so callers don't need to handle it.
+    Suppresses ``CancelledError`` from the cancelled *task* but re-raises
+    if the **current** task was itself cancelled (to avoid swallowing an
+    outer cancellation signal — required for correct behaviour on
+    Python 3.12+ where ``_must_cancel`` no longer auto-re-delivers).
     """
     task.cancel()
     try:
         await task
     except asyncio.CancelledError:
-        pass
+        current = asyncio.current_task()
+        if current is not None and current.cancelling() > 0:
+            raise
     except Exception:
         pass  # Already logged elsewhere; prevent unhandled propagation
 
diff --git a/EvoScientist/channels/mixins.py b/EvoScientist/channels/mixins.py
index c538aca..6a0c2a8 100644
--- a/EvoScientist/channels/mixins.py
+++ b/EvoScientist/channels/mixins.py
@@ -252,7 +252,9 @@ class WebSocketMixin:
             try:
                 await task
             except asyncio.CancelledError:
-                pass
+                current = asyncio.current_task()
+                if current is not None and current.cancelling() > 0:
+                    raise
             except Exception:
                 pass
 
@@ -315,6 +317,8 @@ class PollingMixin:
             try:
                 await task
             except asyncio.CancelledError:
-                pass
+                current = asyncio.current_task()
+                if current is not None and current.cancelling() > 0:
+                    raise
             except Exception:
                 pass