diff --git a/pyproject.toml b/pyproject.toml
index 8f21c1c6..2d084e0a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -126,3 +126,4 @@ isort.required-imports = ["from __future__ import annotations"]
 "**.ipynb" = ["B008", "T20", "I002", "E402", "E703", "B018"]
 "src/egamma_tnp/nanoaod_efficiency.py" = ["PLW2901"]
 "src/egamma_tnp/__init__.py" = ["E402"]
+"tests/example_extra_filter.py" = ["T201"]
diff --git a/src/egamma_tnp/utils/runner_utils.py b/src/egamma_tnp/utils/runner_utils.py
index 9a032e5c..a8c0d9a2 100644
--- a/src/egamma_tnp/utils/runner_utils.py
+++ b/src/egamma_tnp/utils/runner_utils.py
@@ -92,6 +92,37 @@ def filter_class_args(class_, args):
     return {k: v for k, v in args.items() if k in sig.parameters}
 
 
+def load_function_from_file(function_path):
+    """Load a function from a file and return it."""
+    # Split the file path and function name
+    if "::" in function_path:
+        file_path, function_name = function_path.split("::")
+    else:
+        logger.error(f"Function name not provided in the format 'path::function': {function_path}")
+        raise ValueError(f"Function name not provided in the format 'path::function': {function_path}")
+
+    # Check if the file exists
+    if not os.path.exists(file_path):
+        logger.error(f"Function file not found: {file_path}")
+        raise FileNotFoundError(f"Function file not found: {file_path}")
+
+    # Load and execute the file content
+    with open(file_path) as file:
+        code = compile(file.read(), file_path, "exec")
+        local_scope = {}  # Use a restricted local scope
+        exec(code, {}, local_scope)  # Execute code in isolated scope
+
+        # Return the function if a name is provided, otherwise return all loaded objects
+        if function_name:
+            if function_name in local_scope:
+                return local_scope[function_name]
+            else:
+                logger.error(f"Function '{function_name}' not found in {file_path}")
+                raise ValueError(f"Function '{function_name}' not found in {file_path}")
+        else:
+            return local_scope
+
+
 def initialize_class(config, args, fileset):
     """Initialize the appropriate Tag and Probe class based on the workflow specified in the config."""
     class_map = {
@@ -104,6 +135,9 @@ def initialize_class(config, args, fileset):
     workflow = class_map[class_name]
     class_args = config["workflow_args"] | filter_class_args(workflow, vars(args))
     class_args.pop("fileset")
+    if args.extra_filter:
+        extra_filter = load_function_from_file(args.extra_filter)
+        class_args["extra_filter"] = extra_filter
     logger.info(f"Initializing workflow {workflow} with args: {class_args}")
     return workflow(fileset=fileset, **class_args)
 
diff --git a/tests/example_extra_filter.py b/tests/example_extra_filter.py
new file mode 100644
index 00000000..27af99cd
--- /dev/null
+++ b/tests/example_extra_filter.py
@@ -0,0 +1,8 @@
+from __future__ import annotations
+
+
+def extra_filter(events, extra_filter_arg1, extra_filter_arg2):
+    print("I'm an extra filter")
+    print(f"extra_filter_arg1: {extra_filter_arg1}")
+    print(f"extra_filter_arg2: {extra_filter_arg2}")
+    return events
diff --git a/tests/example_settings.json b/tests/example_settings.json
index bae5b7c2..f4fb91e0 100644
--- a/tests/example_settings.json
+++ b/tests/example_settings.json
@@ -6,8 +6,11 @@
     "cutbased_id": null,
     "extra_tags_mask": null,
     "extra_probes_mask": null,
-    "extra_filter": null,
-    "extra_filter_args": {},
+    "extra_filter": "tests/example_extra_filter.py::extra_filter",
+    "extra_filter_args": {
+        "extra_filter_arg1": 1,
+        "extra_filter_arg2": 2
+    },
     "use_sc_eta": true,
     "use_sc_phi": false,
     "avoid_ecal_transition_tags": true,