diff --git a/nireports/reportlets/modality/dwi.py b/nireports/reportlets/modality/dwi.py
index 63258db5..84465e82 100644
--- a/nireports/reportlets/modality/dwi.py
+++ b/nireports/reportlets/modality/dwi.py
@@ -524,7 +524,7 @@ def get_segments(
         indices = np.array([], dtype=int)
         for ii in idx:
             indices = np.concatenate(
-                [indices, np.nonzero(segment_mask == ii)]
+                [indices, np.nonzero(segment_mask == ii)[0]]
             )
         segments[label] = indices