diff --git a/audb/core/config.py b/audb/core/config.py
index 737f91f0..5012b1ca 100644
--- a/audb/core/config.py
+++ b/audb/core/config.py
@@ -35,7 +35,7 @@ def load_configuration_file(config_file: str) -> dict:
         return {}
 
     with open(config_file) as cf:
-        config = yaml.load(cf, Loader=yaml.BaseLoader)
+        config = yaml.load(cf, Loader=yaml.SafeLoader)
         if config is None:
             return {}
 
diff --git a/audb/core/define.py b/audb/core/define.py
index 4dab8d2f..5352cdcb 100644
--- a/audb/core/define.py
+++ b/audb/core/define.py
@@ -76,6 +76,7 @@
 TIMEOUT = 86400  # 24 h
 CACHED_VERSIONS_TIMEOUT = 10  # Timeout to acquire access to cached versions
 LOCK_FILE = ".lock"
+COMPLETE_FILE = ".complete"
 TIMEOUT_MSG = "Lock could not be acquired. Timeout exceeded."
 
 
diff --git a/audb/core/load.py b/audb/core/load.py
index b4af0567..97a0a40d 100644
--- a/audb/core/load.py
+++ b/audb/core/load.py
@@ -182,6 +182,12 @@ def check() -> bool:
         return complete
 
     if check():
+        # Create .complete file to mark database as complete
+        complete_file = os.path.join(db_root, define.COMPLETE_FILE)
+        open(complete_file, "w").close()
+
+        # Keep updating the header file for backwards compatibility
+        # with older versions of audb
         db_root_tmp = database_tmp_root(db_root)
         db.meta["audb"]["complete"] = True
         db_original = audformat.Database.load(db_root, load_data=False)
@@ -197,6 +203,14 @@ def check() -> bool:
 def _database_is_complete(
     db: audformat.Database,
 ) -> bool:
+    # First check for .complete file
+    if "audb" in db.meta and "root" in db.meta["audb"]:
+        db_root = db.meta["audb"]["root"]
+        complete_file = os.path.join(db_root, define.COMPLETE_FILE)
+        if os.path.exists(complete_file):
+            return True
+
+    # Fall back to checking header for backwards compatibility
     complete = False
     if "audb" in db.meta:
         if "complete" in db.meta["audb"]:
diff --git a/tests/test_load.py b/tests/test_load.py
index 3a3f6d61..99985016 100644
--- a/tests/test_load.py
+++ b/tests/test_load.py
@@ -984,3 +984,39 @@ def test_repository(persistent_repository, name, version, error, error_msg):
     else:
         repository = audb.repository(name, version)
         assert repository == persistent_repository
+
+
+def test_database_complete_file(tmpdir, persistent_repository):
+    """Test database completeness mechanism with .complete file.
+
+    This test checks if:
+    1. A .complete file is created when loading a complete database
+    2. The _database_is_complete function returns True when the .complete file exists
+    3. The completeness check still works via the header for backward compatibility
+    """
+    # Load a database fully to create the .complete file
+    db = audb.load(DB_NAME, version="1.0.0", cache_root=tmpdir)
+
+    # Get the database root folder path
+    db_root = audb.core.cache.database_cache_root(DB_NAME, "1.0.0", cache_root=tmpdir)
+
+    # Check if .complete file exists
+    complete_file = os.path.join(db_root, audb.core.define.COMPLETE_FILE)
+    assert os.path.exists(complete_file), "The .complete file was not created"
+
+    # Check if the complete flag is also set in the header (for backward compatibility)
+    from audb.core.load import _database_is_complete
+
+    assert _database_is_complete(db), "Database is not marked as complete"
+
+    # Remove .complete file but keep the header flag to test backward compatibility
+    os.remove(complete_file)
+    assert not os.path.exists(complete_file), "The .complete file could not be removed"
+    assert _database_is_complete(
+        db
+    ), "Backward compatibility with header flag not working"
+
+    # Load the database again - this should recreate the .complete file
+    # as the database detects it's complete from the header flag
+    db = audb.load(DB_NAME, version="1.0.0", cache_root=tmpdir)
+    assert os.path.exists(complete_file), "The .complete file was not recreated"