diff --git a/radicale/sharing/__init__.py b/radicale/sharing/__init__.py
index 43d4da94..9c0bf99e 100644
--- a/radicale/sharing/__init__.py
+++ b/radicale/sharing/__init__.py
@@ -281,7 +281,8 @@ class BaseSharing:
 
     def database_delete_sharing(self,
                                 ShareType: str,
-                                PathOrToken: str) -> dict:
+                                PathOrToken: str,
+                                User: str) -> dict:
         """ delete sharing """
         return {"status": "not-implemented"}
 
@@ -1223,7 +1224,8 @@ class BaseSharing:
             if user == share['Owner']:
                 result = self.database_delete_sharing(
                        ShareType=ShareType,
-                       PathOrToken=PathOrToken) # verification above that it is not None
+                       PathOrToken=PathOrToken,
+                       User=share['Owner']) # verification above that it is not None
             else:
                 # only owner is permitted to delete a share
                 logger.warning(api_info + ": %r not permitted for user %r", PathOrToken, user)
diff --git a/radicale/sharing/csv.py b/radicale/sharing/csv.py
index 3c3d3c18..ccfd448c 100644
--- a/radicale/sharing/csv.py
+++ b/radicale/sharing/csv.py
@@ -371,12 +371,13 @@ class Sharing(sharing.BaseSharing):
 
     def database_delete_sharing(self,
                                 ShareType: str,
-                                PathOrToken: str) -> dict:
+                                PathOrToken: str,
+                                User: str) -> dict:
         """ delete sharing """
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("TRACE/sharing/%s/delete: PathOrToken=%r", ShareType, PathOrToken)
 
-        with self._storage.acquire_lock("w", path=self._sharing_db_file):
+        with self._storage.acquire_lock("w", User, path=self._sharing_db_file):
             # lookup token
             found = False
             index = 0
diff --git a/radicale/sharing/files.py b/radicale/sharing/files.py
index 13ca15a6..06b999d1 100644
--- a/radicale/sharing/files.py
+++ b/radicale/sharing/files.py
@@ -362,7 +362,8 @@ class Sharing(sharing.BaseSharing):
 
     def database_delete_sharing(self,
                                 ShareType: str,
-                                PathOrToken: str) -> dict:
+                                PathOrToken: str,
+                                User: str) -> dict:
         """ delete sharing """
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("TRACE/sharing/%s/delete: PathOrToken=%r", ShareType, PathOrToken)
@@ -372,8 +373,8 @@ class Sharing(sharing.BaseSharing):
         if not os.path.isfile(sharing_config_file):
             return {"status": "not-found"}
 
-        # read content
-        with self._storage.acquire_lock("r", path=sharing_config_file):
+        # open writable so storage hook triggers
+        with self._storage.acquire_lock("w", User, path=sharing_config_file):
             # read file
             with open(sharing_config_file, "rb") as fb:
                 (version, row) = pickle.load(fb)