diff --git a/ipynbsrv/core/signals/container_images.py b/ipynbsrv/core/signals/container_images.py
index bc2367d..16dcc8b 100644
--- a/ipynbsrv/core/signals/container_images.py
+++ b/ipynbsrv/core/signals/container_images.py
@@ -56,7 +56,7 @@ def delete_on_server(sender, image, **kwargs):
                 try:
                     # FIXME: isn't deleted....
                     backend = server.get_container_backend()
-                    backend.delete_container_image(image.backend_pk, True)
+                    backend.delete_container_image(image.backend_pk)
                 except ContainerImageNotFoundError:
                     pass  # already removed
                 except ContainerBackendError as ex:
diff --git a/ipynbsrv/core/signals/container_snapshots.py b/ipynbsrv/core/signals/container_snapshots.py
index ed2e949..bc9bb50 100644
--- a/ipynbsrv/core/signals/container_snapshots.py
+++ b/ipynbsrv/core/signals/container_snapshots.py
@@ -34,7 +34,7 @@ def delete_on_server(sender, snapshot, **kwargs):
     if snapshot is not None:
         backend = snapshot.container.server.get_container_backend()
         try:
-            backend.delete_container_snapshot(snapshot.backend_pk, True)
+            backend.delete_container_snapshot(snapshot.backend_pk)
         except ContainerSnapshotNotFoundError as ex:
             pass  # already removed?
         except ContainerBackendError as ex:
diff --git a/ipynbsrv/core/signals/containers.py b/ipynbsrv/core/signals/containers.py
index a752bd9..b7dc19f 100644
--- a/ipynbsrv/core/signals/containers.py
+++ b/ipynbsrv/core/signals/containers.py
@@ -112,7 +112,7 @@ def delete_on_server(sender, container, **kwargs):
             pass
 
         try:
-            container.server.get_container_backend().delete_container(container.backend_pk, True)
+            container.server.get_container_backend().delete_container(container.backend_pk)
         except ContainerNotFoundError as ex:
             pass  # already deleted
         except ContainerBackendError as ex:
@@ -146,7 +146,7 @@ def restart_on_server(sender, container, **kwargs):
     """
     if container is not None:
         try:
-            container.server.get_container_backend().restart_container(container.backend_pk, True)
+            container.server.get_container_backend().restart_container(container.backend_pk)
         except ContainerBackendError as ex:
             raise ex
 
@@ -158,7 +158,7 @@ def resume_on_server(sender, container, **kwargs):
     """
     if container is not None:
         try:
-            container.server.get_container_backend().resume_container(container.backend_pk, True)
+            container.server.get_container_backend().resume_container(container.backend_pk)
         except ContainerBackendError as ex:
             raise ex
 
@@ -182,7 +182,7 @@ def stop_on_server(sender, container, **kwargs):
     """
     if container is not None:
         try:
-            container.server.get_container_backend().stop_container(container.backend_pk, True)
+            container.server.get_container_backend().stop_container(container.backend_pk)
         except ContainerBackendError as ex:
             raise ex
 
@@ -194,7 +194,7 @@ def suspend_on_server(sender, container, **kwargs):
     """
     if container is not None:
         try:
-            container.server.get_container_backend().suspend_container(container.backend_pk, True)
+            container.server.get_container_backend().suspend_container(container.backend_pk)
         except ContainerBackendError as ex:
             raise ex