diff --git a/piker/_cacheables.py b/piker/_cacheables.py
index d86b477d..47ffa6a4 100644
--- a/piker/_cacheables.py
+++ b/piker/_cacheables.py
@@ -36,6 +36,7 @@ from contextlib import (
 
 import trio
 from trio_typing import TaskStatus
+import tractor
 from tractor._portal import maybe_open_nursery
 
 from .brokers import get_brokermod
@@ -180,43 +181,49 @@ async def maybe_open_ctx(
 
     ctx_key = id(mngr)
 
-    # TODO: does this need to be a tractor "root nursery"?
-    async with maybe_open_nursery(cache.nurseries.get(ctx_key)) as n:
-        cache.nurseries[ctx_key] = n
 
-        value = None
-        try:
-            # lock feed acquisition around task racing  / ``trio``'s
-            # scheduler protocol
-            value = cache.values[key]
-            log.info(f'Reusing cached feed for {key}')
-            cache.users += 1
-            cache.lock.release()
-            yield True, value
+    value = None
+    try:
+        # lock feed acquisition around task racing  / ``trio``'s
+        # scheduler protocol
+        value = cache.values[key]
+        log.info(f'Reusing cached feed for {key}')
+        cache.users += 1
+        cache.lock.release()
+        yield True, value
 
-        except KeyError:
-            log.info(f'Allocating new feed for {key}')
+    except KeyError:
+        log.info(f'Allocating new feed for {key}')
 
-            # **critical section** that should prevent other tasks from
-            # checking the cache until complete otherwise the scheduler
-            # may switch and by accident we create more then one feed.
+        # **critical section** that should prevent other tasks from
+        # checking the cache until complete otherwise the scheduler
+        # may switch and by accident we create more then one feed.
 
-            value = await n.start(cache.run_ctx, mngr, key)
-            cache.users += 1
+        # TODO: vaoid pulling from ``tractor`` internals and
+        # instead offer a "root nursery" in 
+        service_n = tractor.current_actor()._service_n
+
+        # TODO: does this need to be a tractor "root nursery"?
+        ln = cache.nurseries.get(ctx_key)
+        assert not ln
+        ln = cache.nurseries[ctx_key] = service_n
+
+        value = await ln.start(cache.run_ctx, mngr, key)
+        cache.users += 1
+        cache.lock.release()
+
+        yield False, value
+
+    finally:
+        cache.users -= 1
+
+        if cache.lock.locked():
             cache.lock.release()
 
-            yield False, value
+        if value is not None:
+            # if no more consumers, teardown the client
+            if cache.users <= 0:
+                log.warning(f'De-allocating feed for {key}')
 
-        finally:
-            cache.users -= 1
-
-            if cache.lock.locked():
-                cache.lock.release()
-
-            if value is not None:
-                # if no more consumers, teardown the client
-                if cache.users <= 0:
-                    log.warning(f'De-allocating feed for {key}')
-
-                    # terminate mngr nursery
-                    cache.no_more_users.set()
+                # terminate mngr nursery
+                cache.no_more_users.set()