diff --git a/src/supervision/detection/tools/csv_sink.py b/src/supervision/detection/tools/csv_sink.py
index d06d896692..b242636245 100644
--- a/src/supervision/detection/tools/csv_sink.py
+++ b/src/supervision/detection/tools/csv_sink.py
@@ -144,7 +144,13 @@ def parse_detection_data(
                         row[key] = value[i] if hasattr(value, "__getitem__") else value
 
             if custom_data:
-                row.update(custom_data)
+                for key, value in custom_data.items():
+                    if isinstance(value, np.ndarray) and value.ndim == 0:
+                        row[key] = value
+                    elif isinstance(value, np.ndarray):
+                        row[key] = value[i]
+                    else:
+                        row[key] = value
             parsed_rows.append(row)
         return parsed_rows
 
diff --git a/src/supervision/detection/tools/json_sink.py b/src/supervision/detection/tools/json_sink.py
index 5a34e16eaa..4cdbb30354 100644
--- a/src/supervision/detection/tools/json_sink.py
+++ b/src/supervision/detection/tools/json_sink.py
@@ -118,7 +118,13 @@ def parse_detection_data(
                         )
 
             if custom_data:
-                row.update(custom_data)
+                for key, value in custom_data.items():
+                    if isinstance(value, np.ndarray) and value.ndim == 0:
+                        row[key] = str(value)
+                    elif isinstance(value, np.ndarray):
+                        row[key] = str(value[i])
+                    else:
+                        row[key] = value
             parsed_rows.append(row)
         return parsed_rows
 
diff --git a/tests/detection/test_csv.py b/tests/detection/test_csv.py
index 12d52058e7..127352e99a 100644
--- a/tests/detection/test_csv.py
+++ b/tests/detection/test_csv.py
@@ -2,6 +2,7 @@
 import os
 from typing import Any
 
+import numpy as np
 import pytest
 
 import supervision as sv
@@ -193,6 +194,36 @@
                 ],
             ],
         ),  # Complex Data
+        (
+            _create_detections(
+                xyxy=[[10, 20, 30, 40], [50, 60, 70, 80]],
+                confidence=[0.9, 0.8],
+                class_id=[0, 1],
+            ),
+            {"area": np.array([400.0, 400.0])},
+            _create_detections(
+                xyxy=[[15, 25, 35, 45]],
+                confidence=[0.7],
+                class_id=[2],
+            ),
+            {"area": np.array([400.0])},
+            "test_detections_array_custom_data.csv",
+            [
+                [
+                    "x_min",
+                    "y_min",
+                    "x_max",
+                    "y_max",
+                    "class_id",
+                    "confidence",
+                    "tracker_id",
+                    "area",
+                ],
+                ["10.0", "20.0", "30.0", "40.0", "0", "0.9", "", "400.0"],
+                ["50.0", "60.0", "70.0", "80.0", "1", "0.8", "", "400.0"],
+                ["15.0", "25.0", "35.0", "45.0", "2", "0.7", "", "400.0"],
+            ],
+        ),  # numpy array in custom_data sliced per detection row
     ],
 )
 def test_csv_sink(