diff --git a/parakeet/training/chekpoint.py b/parakeet/training/checkpoint.py
similarity index 96%
rename from parakeet/training/chekpoint.py
rename to parakeet/training/checkpoint.py
index 8a5fe4f..155261d 100644
--- a/parakeet/training/chekpoint.py
+++ b/parakeet/training/checkpoint.py
@@ -58,8 +58,8 @@ class KBest(object):
 
     def __init__(self,
                  max_size: int=5,
-                 save_fn: Callable=None,
-                 del_fn: Callable=lambda f: f.unlink()):
+                 save_fn: Callable[[Path], None]=None,
+                 del_fn: Callable[[Path], None]=lambda f: f.unlink()):
         self.best_records: Mapping[Path, float] = {}
         self.save_fn = save_fn
         self.del_fn = del_fn
diff --git a/tests/test_checkpoint.py b/tests/test_checkpoint.py
index 45137d5..af8df02 100644
--- a/tests/test_checkpoint.py
+++ b/tests/test_checkpoint.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from parakeet.training.chekpoint import KBest
+from parakeet.training.checkpoint import KBest
 import numpy as np
 from pathlib import Path
 import shutil