diff --git a/itkwidgets/cell_watcher.py b/itkwidgets/cell_watcher.py
index 7cbbc440..6131a241 100644
--- a/itkwidgets/cell_watcher.py
+++ b/itkwidgets/cell_watcher.py
@@ -22,9 +22,11 @@ def data(self):
     def not_created(self):
         # Return a list of names of viewers that have not been created yet
         names = []
-        for vals in self.data.values():
-            if vals['name'] is not None and not vals['status']:
-                names.append(vals['name'])
+        for key, val in self.data.items():
+            name = val['name']
+            if not val['status']:
+                name = name if name is not None else key
+                names.append(name)
         return names
 
     @property
@@ -122,7 +124,7 @@ def create_task(self, fn):
 
     def capture_event(self, stream, ident, parent):
         self._events.put((stream, ident, parent))
-        if self._events.qsize() == 1 and self.ready_to_run_next_cell(parent):
+        if self._events.qsize() == 1 and self.ready_to_run_next_cell():
             # We've added a new task to an empty queue.
             # Begin executing tasks again.
             self.create_task(self.execute_next_request)
@@ -137,12 +139,10 @@ def all_getters_resolved(self):
         getters_resolved = [f.done() for f in self.results.values()]
         return all(getters_resolved)
 
-    def ready_to_run_next_cell(self, parent):
+    def ready_to_run_next_cell(self):
         # Any itk_viewer objects need to be available and all getters/setters
         # need to be resolved
-        raw = parent.get("content", {}).get("code", "")
-        viewers_not_ready = [n for n in self.viewers.not_created if n in raw]
-        self.waiting_on_viewer = any(viewers_not_ready)
+        self.waiting_on_viewer = len(self.viewers.not_created)
         return self.all_getters_resolved and not self.waiting_on_viewer
 
     async def execute_next_request(self):
@@ -155,7 +155,7 @@ async def execute_next_request(self):
             # Fetch the next request if we haven't already
             self.current_request = self._events.get()
 
-        if self.ready_to_run_next_cell(self.current_request[2]):
+        if self.ready_to_run_next_cell():
             # Continue processing the remaining queued tasks
             await self._execute_next_request()