diff --git a/src/openeo_aggregator/partitionedjobs/zookeeper.py b/src/openeo_aggregator/partitionedjobs/zookeeper.py
index c93269a5..a14230de 100644
--- a/src/openeo_aggregator/partitionedjobs/zookeeper.py
+++ b/src/openeo_aggregator/partitionedjobs/zookeeper.py
@@ -95,15 +95,16 @@ def obtain_new_pjob_id(self, user_id: str, initial_value: bytes = b"", attempts:
         """Obtain new, unique partitioned job id"""
         # A couple of pjob_id attempts: start with current time based name and a suffix to counter collisions (if any)
         base_pjob_id = "pj-" + Clock.utcnow().strftime("%Y%m%d-%H%M%S")
-        for pjob_id in [base_pjob_id] + [f"{base_pjob_id}-{i}" for i in range(1, attempts)]:
-            try:
-                self._client.create(path=self._path(user_id, pjob_id), value=initial_value, makepath=True)
-                # We obtained our unique id
-                return pjob_id
-            except NodeExistsError:
-                # TODO: check that NodeExistsError is thrown on existing job_ids
-                # TODO: add a sleep() to back off a bit?
-                continue
+        with self._connect():
+            for pjob_id in [base_pjob_id] + [f"{base_pjob_id}-{i}" for i in range(1, attempts)]:
+                try:
+                    self._client.create(path=self._path(user_id, pjob_id), value=initial_value, makepath=True)
+                    # We obtained our unique id
+                    return pjob_id
+                except NodeExistsError:
+                    # TODO: check that NodeExistsError is thrown on existing job_ids
+                    # TODO: add a sleep() to back off a bit?
+                    continue
         raise PartitionedJobFailure("Too much attempts to create new pjob_id")
 
     def insert(self, user_id: str, pjob: PartitionedJob) -> str:
@@ -147,12 +148,13 @@ def insert_sjob(
         title: Optional[str] = None,
         status: str = STATUS_INSERTED,
     ):
-        self._client.create(
-            path=self._path(user_id, pjob_id, "sjobs", sjob_id),
-            value=self.serialize(process_graph=subjob.process_graph, backend_id=subjob.backend_id, title=title),
-            makepath=True,
-        )
-        self.set_sjob_status(user_id=user_id, pjob_id=pjob_id, sjob_id=sjob_id, status=status, create=True)
+        with self._connect():
+            self._client.create(
+                path=self._path(user_id, pjob_id, "sjobs", sjob_id),
+                value=self.serialize(process_graph=subjob.process_graph, backend_id=subjob.backend_id, title=title),
+                makepath=True,
+            )
+            self.set_sjob_status(user_id=user_id, pjob_id=pjob_id, sjob_id=sjob_id, status=status, create=True)
 
     def get_pjob_metadata(self, user_id: str, pjob_id: str) -> dict:
         """Get metadata of partitioned job, given by storage id."""
diff --git a/src/openeo_aggregator/testing.py b/src/openeo_aggregator/testing.py
index 77e3df59..54db1bfb 100644
--- a/src/openeo_aggregator/testing.py
+++ b/src/openeo_aggregator/testing.py
@@ -32,7 +32,12 @@ def stop(self):
         assert self.state == "open"
         self.state = "closed"
 
+    def _assert_open(self):
+        if not self.state == "open":
+            raise kazoo.exceptions.ConnectionClosedError("Connection has been closed")
+
     def create(self, path: str, value, makepath: bool = False):
+        self._assert_open()
         if path in self.data:
             raise kazoo.exceptions.NodeExistsError()
         parent = str(pathlib.Path(path).parent)
@@ -44,20 +49,24 @@ def create(self, path: str, value, makepath: bool = False):
         self.data[path] = value
 
     def exists(self, path):
+        self._assert_open()
         return path in self.data
 
     def get(self, path):
+        self._assert_open()
         if path not in self.data:
             raise kazoo.exceptions.NoNodeError()
         return (self.data[path], None)
 
     def get_children(self, path):
+        self._assert_open()
         if path not in self.data:
             raise kazoo.exceptions.NoNodeError()
         parent = path.split("/")
         return [p.split("/")[-1] for p in self.data if p.split("/")[:-1] == parent]
 
     def set(self, path, value, version=-1):
+        self._assert_open()
         if path not in self.data:
             raise kazoo.exceptions.NoNodeError()
         self.data[path] = value