diff --git a/nerfstudio/data/utils/data_utils.py b/nerfstudio/data/utils/data_utils.py
index d1a6721844..1ad67fdc16 100644
--- a/nerfstudio/data/utils/data_utils.py
+++ b/nerfstudio/data/utils/data_utils.py
@@ -38,7 +38,7 @@ def pil_to_numpy(im: PILImage) -> np.ndarray:
 
     # Unpack data
     e = Image._getencoder(im.mode, "raw", im.mode)
-    e.setimage(im.im)
+    e.setimage(im.im, (0, 0) + im.size)
 
     # NumPy buffer for the result
     shape, typestr = Image._conv_type_shape(im)
diff --git a/tests/utils/test_data_utils.py b/tests/utils/test_data_utils.py
new file mode 100644
index 0000000000..e12973eb4a
--- /dev/null
+++ b/tests/utils/test_data_utils.py
@@ -0,0 +1,38 @@
+# Copyright 2026 the Regents of the University of California, Nerfstudio Team and contributors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import numpy as np
+import pytest
+from PIL import Image
+
+from nerfstudio.data.utils.data_utils import pil_to_numpy
+
+
+@pytest.mark.parametrize(
+    "values",
+    [
+        np.array([[1, 2], [3, 4]], dtype=np.uint8),
+        np.array(
+            [[[1, 2, 3], [4, 5, 6]], [[7, 8, 9], [10, 11, 12]]],
+            dtype=np.uint8,
+        ),
+    ],
+)
+def test_pil_to_numpy(values):
+    image = Image.fromarray(values)
+
+    result = pil_to_numpy(image)
+
+    np.testing.assert_array_equal(result, values)
+    assert result.flags.writeable