diff --git a/movement/io/load_bboxes.py b/movement/io/load_bboxes.py
index 0b18aac0..437e35d5 100644
--- a/movement/io/load_bboxes.py
+++ b/movement/io/load_bboxes.py
@@ -13,7 +13,11 @@
 
 from movement.utils.logging import log_error
 from movement.validators.datasets import ValidBboxesDataset
-from movement.validators.files import ValidFile, ValidVIATracksCSV
+from movement.validators.files import (
+    DEFAULT_FRAME_REGEXP,
+    ValidFile,
+    ValidVIATracksCSV,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -349,7 +353,7 @@ def from_via_tracks_file(
 
 
 def _numpy_arrays_from_via_tracks_file(
-    file_path: Path, frame_regexp: str = r"(0\d*)\.\w+$"
+    file_path: Path, frame_regexp: str = DEFAULT_FRAME_REGEXP
 ) -> dict:
     """Extract numpy arrays from the input VIA tracks .csv file.
 
@@ -427,7 +431,7 @@ def _numpy_arrays_from_via_tracks_file(
 
 
 def _df_from_via_tracks_file(
-    file_path: Path, frame_regexp: str = r"(0\d*)\.\w+$"
+    file_path: Path, frame_regexp: str = DEFAULT_FRAME_REGEXP
 ) -> pd.DataFrame:
     """Load VIA tracks .csv file as a dataframe.
 
@@ -526,7 +530,7 @@ def _extract_confidence_from_via_tracks_df(df: pd.DataFrame) -> np.ndarray:
 
 
 def _extract_frame_number_from_via_tracks_df(
-    df: pd.DataFrame, frame_regexp: str = r"(0\d*)\.\w+$"
+    df: pd.DataFrame, frame_regexp: str = DEFAULT_FRAME_REGEXP
 ) -> np.ndarray:
     """Extract frame numbers from the VIA tracks input dataframe.
 
diff --git a/movement/validators/files.py b/movement/validators/files.py
index 6a910010..dd603b22 100644
--- a/movement/validators/files.py
+++ b/movement/validators/files.py
@@ -12,6 +12,8 @@
 
 from movement.utils.logging import log_error
 
+DEFAULT_FRAME_REGEXP = r"(0\d*)\.\w+$"
+
 
 @define
 class ValidFile: