diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7871e346..0a973ff0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -160,7 +160,7 @@ jobs:
       # tractor` must succeed everywhere, and `HAS_UDS` reflects
       # platform capability (False on Windows, True on POSIX).
       - name: 'Smoke: import tractor'
-        run: uv run python -c "import tractor; from tractor.ipc._uds import HAS_UDS; print('import tractor OK | HAS_UDS=', HAS_UDS)"
+        run: uv run python -c "import sys; import tractor; from tractor.ipc._uds import HAS_UDS; assert sys.platform != 'win32' or not HAS_UDS; print('import tractor OK | HAS_UDS=', HAS_UDS)"
 
       - name: Run tests
         run: >
diff --git a/tractor/ipc/_uds.py b/tractor/ipc/_uds.py
index 3d5a3c8e..262cc2e1 100644
--- a/tractor/ipc/_uds.py
+++ b/tractor/ipc/_uds.py
@@ -115,10 +115,12 @@ _SUN_PATH_LIMIT: int = (
 
 
 # single source of truth for "is the UDS backend usable on this
-# host?" — reuse `trio`'s `has_unix` (the same predicate that gates
-# `trio.open_unix_socket()`) rather than re-deriving an `AF_UNIX`
-# probe in every consumer module.
-HAS_UDS: bool = has_unix
+# host?" Windows can expose `AF_UNIX`, but this backend remains
+# POSIX-only until its credential and lifecycle paths are supported.
+HAS_UDS: bool = (
+    sys.platform != 'win32'
+    and has_unix
+)
 
 
 def unwrap_sockpath(