diff --git a/CHANGES.rst b/CHANGES.rst
index a2d2af7e..d815f950 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,9 +1,13 @@
+Added
+^^^^^
+- `env_prefix` create_app variable can select the environment var prefix.
+
 [0.0.52] - 2024-04-22
 ---------------------
 
 Added
 ^^^^^
-- `ENV_FILE` environment variable can customize/disable the .env file
+- `env_file` create_app variable can customize/disable the .env file
 
 Changed
 ^^^^^^^
diff --git a/canaille/__init__.py b/canaille/__init__.py
index cf8f3088..84103f61 100644
--- a/canaille/__init__.py
+++ b/canaille/__init__.py
@@ -124,7 +124,9 @@ def setup_flask_converters(app):
         app.url_map.converters[model_name.lower()] = model_converter(model_class)
 
 
-def create_app(config=None, validate=True, backend=None):
+def create_app(
+    config=None, validate=True, backend=None, env_file=".env", env_prefix=""
+):
     from .app.configuration import setup_config
     from .app.i18n import setup_i18n
     from .app.themes import setup_themer
@@ -132,7 +134,13 @@ def create_app(config=None, validate=True, backend=None):
 
     app = Flask(__name__)
     with app.app_context():
-        if not setup_config(app, config, validate):  # pragma: no cover
+        if not setup_config(
+            app=app,
+            config=config,
+            test_config=validate,
+            env_file=env_file,
+            env_prefix=env_prefix,
+        ):  # pragma: no cover
             sys.exit(1)
 
     sentry_sdk = setup_sentry(app)
diff --git a/canaille/app/configuration.py b/canaille/app/configuration.py
index 16553fb5..a42c834c 100644
--- a/canaille/app/configuration.py
+++ b/canaille/app/configuration.py
@@ -13,7 +13,6 @@ from pydantic_settings import SettingsConfigDict
 from canaille.core.configuration import CoreSettings
 
 ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
-DEFAULT_ENV_FILE = ".env"
 
 
 class RootSettings(BaseSettings):
@@ -60,10 +59,10 @@ class RootSettings(BaseSettings):
     """
 
 
-def settings_factory(config):
-    """Overly complicated function that pushes the backend specific
-    configuration into CoreSettings, in the purpose break dependency against
-    backends libraries like python-ldap or sqlalchemy."""
+def settings_factory(config, env_file=".env", env_prefix=""):
+    """Pushes the backend specific configuration into CoreSettings, in the
+    purpose break dependency against backends libraries like python-ldap or
+    sqlalchemy."""
     attributes = {"CANAILLE": (CoreSettings, CoreSettings())}
 
     if "CANAILLE_SQL" in config or any(
@@ -93,11 +92,11 @@ def settings_factory(config):
         **attributes,
     )
 
-    env_file = os.getenv("ENV_FILE", config.get("ENV_FILE", DEFAULT_ENV_FILE))
     return Settings(
         **config,
         _secrets_dir=os.environ.get("SECRETS_DIR"),
         _env_file=env_file,
+        _env_prefix=env_prefix,
     )
 
 
@@ -121,7 +120,7 @@ def toml_content(file_path):
         raise Exception("toml library not installed. Cannot load configuration.")
 
 
-def setup_config(app, config=None, test_config=True):
+def setup_config(app, config=None, test_config=True, env_file=".env", env_prefix=""):
     from canaille.oidc.installation import install
 
     app.config.from_mapping(
@@ -135,7 +134,9 @@ def setup_config(app, config=None, test_config=True):
         config = toml_content(os.environ.get("CONFIG"))
 
     try:
-        config_obj = settings_factory(config or {})
+        config_obj = settings_factory(
+            config or {}, env_file=env_file, env_prefix=env_prefix
+        )
     except ValidationError as exc:  # pragma: no cover
         app.logger.critical(str(exc))
         return False
diff --git a/tests/app/test_configuration.py b/tests/app/test_configuration.py
index 0b66ba6f..36c43b9b 100644
--- a/tests/app/test_configuration.py
+++ b/tests/app/test_configuration.py
@@ -41,6 +41,7 @@ def test_configuration_nestedsecrets_directory(tmp_path, backend, configuration)
 
 
 def test_configuration_from_environment_vars():
+    """Canaille should read configuration from environment vars."""
     os.environ["SECRET_KEY"] = "very-very-secret"
     os.environ["CANAILLE__SMTP__FROM_ADDR"] = "user@mydomain.tld"
     os.environ["CANAILLE_SQL__DATABASE_URI"] = "sqlite:///anything.db"
@@ -60,6 +61,22 @@ def test_configuration_from_environment_vars():
     del os.environ["CANAILLE_SQL__DATABASE_URI"]
 
 
+def test_disable_env_var_loading(tmp_path, configuration):
+    """Canaille should not read configuration from environment vars when
+    env_prefix is False."""
+    del configuration["SERVER_NAME"]
+    os.environ["SERVER_NAME"] = "example.com"
+    os.environ["FOOBAR_SERVER_NAME"] = "foobar.example.com"
+
+    app = create_app(configuration, env_prefix="")
+    assert app.config["SERVER_NAME"] == "example.com"
+
+    app = create_app(configuration, env_prefix="FOOBAR_")
+    assert app.config["SERVER_NAME"] == "foobar.example.com"
+
+    del os.environ["SERVER_NAME"]
+
+
 def test_dotenv_file(tmp_path, configuration):
     """Canaille should read configuration from .env files."""
     oldcwd = os.getcwd()
@@ -81,8 +98,7 @@ def test_custom_dotenv_file(tmp_path, configuration):
     with open(dotenv, "w") as fd:
         fd.write("FOOBAR=other-custom-value")
 
-    configuration["ENV_FILE"] = dotenv
-    app = create_app(configuration)
+    app = create_app(configuration, env_file=dotenv)
     assert app.config["FOOBAR"] == "other-custom-value"
 
 
@@ -95,8 +111,7 @@ def test_disable_dotenv_file(tmp_path, configuration):
     with open(dotenv, "w") as fd:
         fd.write("FOOBAR=custom-value")
 
-    configuration["ENV_FILE"] = None
-    app = create_app(configuration)
+    app = create_app(configuration, env_file=None)
     assert "FOOBAR" not in app.config
     os.chdir(oldcwd)