diff --git a/src/aleph/handlers/message_handler.py b/src/aleph/handlers/message_handler.py
index 125cb127..117fa3f2 100644
--- a/src/aleph/handlers/message_handler.py
+++ b/src/aleph/handlers/message_handler.py
@@ -8,7 +8,7 @@
 from aleph_message.models import ItemHash, ItemType, MessageType
 from configmanager import Config
 from pydantic import ValidationError
-from sqlalchemy import insert
+from sqlalchemy.dialects.postgresql import insert
 
 from aleph.chains.signature_verifier import SignatureVerifier
 from aleph.db.accessors.files import insert_content_file_pin, upsert_file
@@ -241,14 +241,29 @@ async def add_pending_message(
                 session.commit()
                 return None
 
+            # Check if there are an already existing record
+            existing_message = (
+                session.query(PendingMessageDb)
+                .filter_by(
+                    sender=pending_message.sender,
+                    item_hash=pending_message.item_hash,
+                    signature=pending_message.signature,
+                )
+                .one_or_none()
+            )
+            if existing_message:
+                return existing_message
+
             upsert_message_status_stmt = make_message_status_upsert_query(
                 item_hash=pending_message.item_hash,
                 new_status=MessageStatus.PENDING,
                 reception_time=reception_time,
                 where=MessageStatusDb.status == MessageStatus.REJECTED,
             )
-            insert_pending_message_stmt = insert(PendingMessageDb).values(
-                pending_message.to_dict(exclude={"id"})
+            insert_pending_message_stmt = (
+                insert(PendingMessageDb)
+                .values(pending_message.to_dict(exclude={"id"}))
+                .on_conflict_do_nothing("uq_pending_message")
             )
 
             try:
@@ -256,23 +271,9 @@ async def add_pending_message(
                 session.execute(insert_pending_message_stmt)
                 session.commit()
             except sqlalchemy.exc.IntegrityError:
-                # Handle the unique constraint violation and log as debug to avoid multiple errors.
-                LOGGER.debug(
-                    "Duplicate pending message detected. Fetching existing record."
-                )
-                session.rollback()
-                # Fetch the existing record
-                existing_message = (
-                    session.query(PendingMessageDb)
-                    .filter_by(
-                        sender=pending_message.sender,
-                        item_hash=pending_message.item_hash,
-                        signature=pending_message.signature,
-                    )
-                    .one_or_none()
-                )
-                if existing_message:
-                    return existing_message
+                # Handle the unique constraint violation.
+                LOGGER.warning("Duplicate pending message detected trying to save it.")
+                return None
 
             except (psycopg2.Error, sqlalchemy.exc.SQLAlchemyError) as e:
                 LOGGER.warning(
diff --git a/tests/message_processing/test_process_pending_messages.py b/tests/message_processing/test_process_pending_messages.py
index 8a0f3889..0cae91bb 100644
--- a/tests/message_processing/test_process_pending_messages.py
+++ b/tests/message_processing/test_process_pending_messages.py
@@ -12,7 +12,7 @@
 
 
 @pytest.mark.asyncio
-async def test_pending_message(
+async def test_duplicated_pending_message(
     mocker,
     mock_config: Config,
     session_factory: DbSessionFactory,