diff --git a/src/mdevaluate/__init__.py b/src/mdevaluate/__init__.py
index 2687fda..8fe6d5a 100644
--- a/src/mdevaluate/__init__.py
+++ b/src/mdevaluate/__init__.py
@@ -5,16 +5,17 @@ from typing import Optional
 import pandas as pd
 
 from . import atoms
+from . import autosave
+from . import checksum
 from . import coordinates
 from . import correlation
 from . import distribution
 from . import functions
 from . import pbc
-from . import autosave
 from . import reader
 from . import system
 from . import utils
-from .extra import free_energy_landscape, chill
+from . import extra
 from .logging import logger
 
 
diff --git a/src/mdevaluate/extra/__init__.py b/src/mdevaluate/extra/__init__.py
index e69de29..8d1d8fb 100644
--- a/src/mdevaluate/extra/__init__.py
+++ b/src/mdevaluate/extra/__init__.py
@@ -0,0 +1,2 @@
+from . import chill
+from . import free_energy_landscape