diff --git a/movement/validators/files.py b/movement/validators/files.py
index 64929361..87d27775 100644
--- a/movement/validators/files.py
+++ b/movement/validators/files.py
@@ -247,7 +247,7 @@ def csv_file_contains_valid_header(self, attribute, value):
 
     @path.validator
     def csv_file_contains_valid_frame_numbers(self, attribute, value):
-        """Ensure that the VIA tracks csv file contains valid frame numbers.
+        """Ensure that the VIA tracks .csv file contains valid frame numbers.
 
         This involves:
         - Checking that frame numbers are included in `file_attributes` or
@@ -309,13 +309,14 @@ def csv_file_contains_valid_frame_numbers(self, attribute, value):
             raise log_error(
                 ValueError,
                 "The number of unique frame numbers does not match the number "
-                "of unique image files. Please review the VIA tracks csv file "
-                "and ensure a unique frame number is defined for each file. ",
+                "of unique image files. Please review the VIA tracks .csv "
+                "file and ensure a unique frame number is defined for each "
+                "file. ",
             )
 
     @path.validator
     def csv_file_contains_tracked_bboxes(self, attribute, value):
-        """Ensure that the VIA tracks csv contains tracked bounding boxes.
+        """Ensure that the VIA tracks .csv contains tracked bounding boxes.
 
         This involves:
         - Checking that the bounding boxes are defined as rectangles.
@@ -365,7 +366,7 @@ def csv_file_contains_tracked_bboxes(self, attribute, value):
                     f"{row.filename} (row {row.Index}): "
                     "bounding box does not have a 'track' attribute defined "
                     "under 'region_attributes'. "
-                    "Please review the VIA tracks csv file.",
+                    "Please review the VIA tracks .csv file.",
                 )
 
             # check track ID is castable as an integer
@@ -376,14 +377,14 @@ def csv_file_contains_tracked_bboxes(self, attribute, value):
                     ValueError,
                     f"{row.filename} (row {row.Index}): "
                     "the track ID for the bounding box cannot be cast "
-                    "as an integer. Please review the VIA tracks csv file.",
+                    "as an integer. Please review the VIA tracks .csv file.",
                 ) from e
 
     @path.validator
     def csv_file_contains_unique_track_IDs_per_filename(
         self, attribute, value
     ):
-        """Ensure the VIA tracks csv contains unique track IDs per filename.
+        """Ensure the VIA tracks .csv contains unique track IDs per filename.
 
         It checks that bounding boxes IDs are defined once per image file.
         """
@@ -406,5 +407,5 @@ def csv_file_contains_unique_track_IDs_per_filename(
                     f"{file}: "
                     "multiple bounding boxes in this file "
                     "have the same track ID. "
-                    "Please review the VIA tracks csv file.",
+                    "Please review the VIA tracks .csv file.",
                 )
diff --git a/tests/conftest.py b/tests/conftest.py
index 8029e4bb..27281b00 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -362,7 +362,7 @@ def via_tracks_csv_with_valid_header(tmp_path):
 def frame_number_in_file_attribute_not_integer(
     via_tracks_csv_with_valid_header,
 ):
-    """Return the file path for a VIA tracks csv file with invalid frame
+    """Return the file path for a VIA tracks .csv file with invalid frame
     number defined as file_attribute.
     """
     file_path = via_tracks_csv_with_valid_header
@@ -383,7 +383,7 @@ def frame_number_in_file_attribute_not_integer(
 def frame_number_in_filename_wrong_pattern(
     via_tracks_csv_with_valid_header,
 ):
-    """Return the file path for a VIA tracks csv file with invalid frame
+    """Return the file path for a VIA tracks .csv file with invalid frame
     number defined in the frame's filename.
     """
     file_path = via_tracks_csv_with_valid_header
@@ -404,7 +404,7 @@ def frame_number_in_filename_wrong_pattern(
 def more_frame_numbers_than_filenames(
     via_tracks_csv_with_valid_header,
 ):
-    """Return the file path for a VIA tracks csv file with more
+    """Return the file path for a VIA tracks .csv file with more
     frame numbers than filenames.
     """
     file_path = via_tracks_csv_with_valid_header
@@ -435,7 +435,7 @@ def more_frame_numbers_than_filenames(
 def less_frame_numbers_than_filenames(
     via_tracks_csv_with_valid_header,
 ):
-    """Return the file path for a VIA tracks csv file with with less
+    """Return the file path for a VIA tracks .csv file with with less
     frame numbers than filenames.
     """
     file_path = via_tracks_csv_with_valid_header
@@ -466,7 +466,7 @@ def less_frame_numbers_than_filenames(
 def region_shape_attribute_not_rect(
     via_tracks_csv_with_valid_header,
 ):
-    """Return the file path for a VIA tracks csv file with invalid shape in
+    """Return the file path for a VIA tracks .csv file with invalid shape in
     region_shape_attributes.
     """
     file_path = via_tracks_csv_with_valid_header
@@ -487,7 +487,7 @@ def region_shape_attribute_not_rect(
 def region_shape_attribute_missing_x(
     via_tracks_csv_with_valid_header,
 ):
-    """Return the file path for a VIA tracks csv file with invalid shape in
+    """Return the file path for a VIA tracks .csv file with missing `x` key in
     region_shape_attributes.
     """
     file_path = via_tracks_csv_with_valid_header
@@ -508,7 +508,7 @@ def region_shape_attribute_missing_x(
 def region_attribute_missing_track(
     via_tracks_csv_with_valid_header,
 ):
-    """Return the file path for a VIA tracks csv file with missing track
+    """Return the file path for a VIA tracks .csv file with missing track
     attribute in region_attributes.
     """
     file_path = via_tracks_csv_with_valid_header
@@ -529,7 +529,7 @@ def region_attribute_missing_track(
 def track_id_not_castable_as_int(
     via_tracks_csv_with_valid_header,
 ):
-    """Return the file path for a VIA tracks csv file with a track ID
+    """Return the file path for a VIA tracks .csv file with a track ID
     attribute not castable as an integer.
     """
     file_path = via_tracks_csv_with_valid_header
@@ -550,7 +550,7 @@ def track_id_not_castable_as_int(
 def track_ids_not_unique_per_frame(
     via_tracks_csv_with_valid_header,
 ):
-    """Return the file path for a VIA tracks csv file with a track ID
+    """Return the file path for a VIA tracks .csv file with a track ID
     that appears twice in the same frame.
     """
     file_path = via_tracks_csv_with_valid_header
diff --git a/tests/test_unit/test_validators/test_files_validators.py b/tests/test_unit/test_validators/test_files_validators.py
index 2f39431b..403a67b3 100644
--- a/tests/test_unit/test_validators/test_files_validators.py
+++ b/tests/test_unit/test_validators/test_files_validators.py
@@ -99,14 +99,14 @@ def test_deeplabcut_csv_validator_with_invalid_input(
         (
             "more_frame_numbers_than_filenames",
             "The number of unique frame numbers does not match the number "
-            "of unique image files. Please review the VIA tracks csv file and "
-            "ensure a unique frame number is defined for each file. ",
+            "of unique image files. Please review the VIA tracks .csv file "
+            "and ensure a unique frame number is defined for each file. ",
         ),
         (
             "less_frame_numbers_than_filenames",
             "The number of unique frame numbers does not match the number "
-            "of unique image files. Please review the VIA tracks csv file and "
-            "ensure a unique frame number is defined for each file. ",
+            "of unique image files. Please review the VIA tracks .csv file "
+            "and ensure a unique frame number is defined for each file. ",
         ),
         (
             "region_shape_attribute_not_rect",
@@ -127,20 +127,20 @@ def test_deeplabcut_csv_validator_with_invalid_input(
             "04.09.2023-04-Right_RE_test_frame_01.png (row 0): "
             "bounding box does not have a 'track' attribute defined "
             "under 'region_attributes'. "
-            "Please review the VIA tracks csv file.",
+            "Please review the VIA tracks .csv file.",
         ),
         (
             "track_id_not_castable_as_int",
             "04.09.2023-04-Right_RE_test_frame_01.png (row 0): "
             "the track ID for the bounding box cannot be cast "
             "as an integer. "
-            "Please review the VIA tracks csv file.",
+            "Please review the VIA tracks .csv file.",
         ),
         (
             "track_ids_not_unique_per_frame",
             "04.09.2023-04-Right_RE_test_frame_01.png: "
             "multiple bounding boxes in this file have the same track ID. "
-            "Please review the VIA tracks csv file.",
+            "Please review the VIA tracks .csv file.",
         ),
     ],
 )
@@ -150,7 +150,7 @@ def test_via_tracks_csv_validator_with_invalid_input(
     """Test that invalid VIA tracks CSV files raise the appropriate errors.
 
     Errors to check:
-    - error if csv header is wrong
+    - error if .csv header is wrong
     - error if frame number is not defined in the file
         (frame number extracted either from the filename or from attributes)
     - error if extracted frame numbers are not 1-based integers