diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3e271ff..d2f6237 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -26,7 +26,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest]
-        python: ['3.7', '3.8']
+        python: ['3.7', '3.8', '3.9']
         spawn_backend: ['trio', 'mp']
     steps:
       - name: Checkout
diff --git a/tractor/_forkserver_override.py b/tractor/_forkserver_override.py
index c515510..25134ff 100644
--- a/tractor/_forkserver_override.py
+++ b/tractor/_forkserver_override.py
@@ -120,7 +120,8 @@ class PatchedForkServer(ForkServer):
             with socket.socket(socket.AF_UNIX) as listener:
                 address = connection.arbitrary_address('AF_UNIX')
                 listener.bind(address)
-                os.chmod(address, 0o600)
+                if not util.is_abstract_socket_namespace(address):
+                    os.chmod(address, 0o600)
                 listener.listen()
 
                 # all client processes own the write end of the "alive" pipe;