diff --git a/.gitignore b/.gitignore
index 295eb22b..9cbfa3b4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,5 @@
 .coverage
 reports/
 __pycache__/
+config/app-merged.yaml
+config/app-custom.yaml
diff --git a/Dockerfile b/Dockerfile
index 1688264f..a7631c04 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,6 +7,7 @@ COPY requirements/prod.txt requirements.txt
 RUN pip install -r requirements.txt
 
 COPY slackhealthbot slackhealthbot
+COPY config/app-default.yaml config/app-default.yaml
 COPY templates templates
 COPY alembic.ini alembic.ini
 COPY alembic alembic
diff --git a/README.md b/README.md
index 49c937f6..b64df189 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,7 @@ Pushes messages to a pre-selected Slack channel, when users log new weight data
 * Create an application in the [Fitbit developer dashboard](https://dev.fitbit.com/apps/).
 * Create an application [on Slack](https://api.slack.com/apps), with a webhook to post messages to a specific channel.
 * Copy the `.env.template` file to `.env`, and modify the values.
+* [Optional]: Copy the `config/app-custom.yaml.template` file to `app-custom.yaml`, and override any values which are defined in `config/app-default.yaml`.
 
 ## Retrieve the docker image
 
@@ -36,7 +37,7 @@ Create a folder on the host where the database will be saved: `/path/to/data/`.
 Run the docker image.
 
 ```
-docker run --detach --publish 8000:8000 -v `pwd`/.env:/app/.env -v /path/to/data/:/tmp/data ghcr.io/caarmen/slack-health-bot
+docker run --detach --publish 8000:8000 -v `pwd`/.env:/app/.env -v `pwd`/app-custom.yaml:/app/config/app-custom.yaml  -v /path/to/data/:/tmp/data ghcr.io/caarmen/slack-health-bot
 ```
 
 ## Using the application
diff --git a/config/app-custom.yaml.template b/config/app-custom.yaml.template
new file mode 100644
index 00000000..f4010e19
--- /dev/null
+++ b/config/app-custom.yaml.template
@@ -0,0 +1,4 @@
+# Place any overrides of the default values, from app-default.yaml, into this file.
+app:
+  logging:
+    sql_log_level: "DEBUG"  # example override: set sql logging to DEBUG
\ No newline at end of file
diff --git a/config/app.yaml b/config/app-default.yaml
similarity index 100%
rename from config/app.yaml
rename to config/app-default.yaml
diff --git a/slackhealthbot/settings.py b/slackhealthbot/settings.py
index c637cc81..affb06fc 100644
--- a/slackhealthbot/settings.py
+++ b/slackhealthbot/settings.py
@@ -2,7 +2,9 @@
 import datetime as dt
 from pathlib import Path
 
+import yaml
 from pydantic import AnyHttpUrl, BaseModel, HttpUrl
+from pydantic.v1.utils import deep_update
 from pydantic_settings import (
     BaseSettings,
     PydanticBaseSettingsSource,
@@ -73,7 +75,27 @@ class AppSettings(BaseSettings):
     app: App
     withings: Withings
     fitbit: Fitbit
-    model_config = SettingsConfigDict(yaml_file="config/app.yaml")
+    model_config = SettingsConfigDict(yaml_file="config/app-merged.yaml")
+
+    @classmethod
+    def _load_yaml_file(
+        cls,
+        path: str,
+        required: bool,
+    ) -> dict:
+        try:
+            with open(path, "r", encoding="utf-8") as file:
+                return yaml.safe_load(file)
+        except OSError as e:
+            if required:
+                raise e
+            return {}
+
+    @classmethod
+    def _load_merged_config(cls) -> dict:
+        default_config = cls._load_yaml_file("config/app-default.yaml", required=True)
+        custom_config = cls._load_yaml_file("config/app-custom.yaml", required=False)
+        return deep_update(default_config, custom_config)
 
     @classmethod
     def settings_customise_sources(
@@ -82,6 +104,9 @@ def settings_customise_sources(
         *args,
         **kwargs,
     ) -> tuple[PydanticBaseSettingsSource, ...]:
+        merged_config = cls._load_merged_config()
+        with open("config/app-merged.yaml", "w", encoding="utf-8") as file:
+            yaml.safe_dump(merged_config, file)
         yaml_settings_source = YamlConfigSettingsSource(settings_cls)
         return (yaml_settings_source,)