diff --git a/swh/provenance/cli.py b/swh/provenance/cli.py
--- a/swh/provenance/cli.py
+++ b/swh/provenance/cli.py
@@ -161,6 +161,7 @@
             lower=reuse,
             mindepth=min_depth,
         )
+    provenance.close()
 
 
 def generate_revision_tuples(
@@ -192,6 +193,7 @@
 
     for origin in origins:
         origin_add(provenance, archive, [origin])
+    provenance.close()
 
 
 def generate_origin_tuples(filename: str) -> Generator[Tuple[str, bytes], None, None]:
@@ -220,6 +222,7 @@
         )
     else:
         print(f"Cannot find a content with the id {swhid}")
+    provenance.close()
 
 
 @cli.command(name="find-all")
@@ -239,3 +242,4 @@
             f"{occur.origin}, "
             f"{os.fsdecode(occur.path)}"
         )
+    provenance.close()
diff --git a/swh/provenance/interface.py b/swh/provenance/interface.py
--- a/swh/provenance/interface.py
+++ b/swh/provenance/interface.py
@@ -65,6 +65,11 @@
 
 @runtime_checkable
 class ProvenanceStorageInterface(Protocol):
+    @remote_api_endpoint("close")
+    def close(self) -> None:
+        """Close connection to the storage and release resources."""
+        ...
+
     @remote_api_endpoint("content_add")
     def content_add(
         self, cnts: Union[Iterable[Sha1Git], Dict[Sha1Git, Optional[datetime]]]
@@ -198,6 +203,10 @@
 class ProvenanceInterface(Protocol):
     storage: ProvenanceStorageInterface
 
+    def close(self) -> None:
+        """Close connection to the underlying `storage` and release resources."""
+        ...
+
     def flush(self) -> None:
         """Flush internal cache to the underlying `storage`."""
         ...
diff --git a/swh/provenance/mongo/backend.py b/swh/provenance/mongo/backend.py
--- a/swh/provenance/mongo/backend.py
+++ b/swh/provenance/mongo/backend.py
@@ -25,6 +25,9 @@
     def __init__(self, db: pymongo.database.Database):
         self.db = db
 
+    def close(self) -> None:
+        pass
+
     def content_add(
         self, cnts: Union[Iterable[Sha1Git], Dict[Sha1Git, Optional[datetime]]]
     ) -> bool:
diff --git a/swh/provenance/postgresql/provenance.py b/swh/provenance/postgresql/provenance.py
--- a/swh/provenance/postgresql/provenance.py
+++ b/swh/provenance/postgresql/provenance.py
@@ -60,6 +60,9 @@
     def denormalized(self) -> bool:
         return "denormalized" in self.flavor
 
+    def close(self) -> None:
+        pass
+
     def content_add(
         self, cnts: Union[Iterable[Sha1Git], Dict[Sha1Git, Optional[datetime]]]
     ) -> bool:
diff --git a/swh/provenance/provenance.py b/swh/provenance/provenance.py
--- a/swh/provenance/provenance.py
+++ b/swh/provenance/provenance.py
@@ -77,6 +77,9 @@
     def clear_caches(self) -> None:
         self.cache = new_cache()
 
+    def close(self) -> None:
+        self.storage.close()
+
     def flush(self) -> None:
         # Revision-content layer insertions ############################################
 
diff --git a/swh/provenance/tests/conftest.py b/swh/provenance/tests/conftest.py
--- a/swh/provenance/tests/conftest.py
+++ b/swh/provenance/tests/conftest.py
@@ -5,7 +5,7 @@
 
 from datetime import datetime, timedelta, timezone
 from os import path
-from typing import Any, Dict, Iterable, Iterator
+from typing import Any, Dict, Generator, Iterable, Iterator
 
 from _pytest.fixtures import SubRequest
 import msgpack
@@ -70,23 +70,28 @@
     provenance_postgresqldb: Dict[str, str],
     mongodb: pymongo.database.Database,
     swh_rpc_client: ProvenanceStorageRPCClient,
-) -> ProvenanceStorageInterface:
+) -> Generator[ProvenanceStorageInterface, None, None]:
     """Return a working and initialized ProvenanceStorageInterface object"""
 
     if request.param == "rpcapi":
         assert isinstance(swh_rpc_client, ProvenanceStorageInterface)
-        return swh_rpc_client
+        yield swh_rpc_client
+        swh_rpc_client.close()
 
     elif request.param == "mongodb":
         from swh.provenance.mongo.backend import ProvenanceStorageMongoDb
 
-        return ProvenanceStorageMongoDb(mongodb)
+        mongodb_storage = ProvenanceStorageMongoDb(mongodb)
+        yield mongodb_storage
+        mongodb_storage.close()
 
     else:
         # in test sessions, we DO want to raise any exception occurring at commit time
-        return get_provenance_storage(
+        storage = get_provenance_storage(
             cls=request.param, db=provenance_postgresqldb, raise_on_commit=True
         )
+        yield storage
+        storage.close()
 
 
 provenance_postgresql = postgresql("postgresql_proc", dbname="provenance_tests")
@@ -95,7 +100,7 @@
 @pytest.fixture
 def provenance(
     provenance_postgresql: psycopg2.extensions.connection,
-) -> ProvenanceInterface:
+) -> Generator[ProvenanceInterface, None, None]:
     """Return a working and initialized ProvenanceInterface object"""
 
     from swh.core.cli.db import populate_database_for_package
@@ -104,11 +109,13 @@
         "swh.provenance", provenance_postgresql.dsn, flavor="with-path"
     )
     # in test sessions, we DO want to raise any exception occurring at commit time
-    return get_provenance(
+    provenance = get_provenance(
         cls="postgresql",
         db=provenance_postgresql.get_dsn_parameters(),
         raise_on_commit=True,
     )
+    yield provenance
+    provenance.close()
 
 
 @pytest.fixture