diff --git a/differt/src/differt/geometry/triangle_mesh.py b/differt/src/differt/geometry/triangle_mesh.py
index c1e15968..7dde3329 100644
--- a/differt/src/differt/geometry/triangle_mesh.py
+++ b/differt/src/differt/geometry/triangle_mesh.py
@@ -482,6 +482,9 @@ def sample(
             replace=replace,
         )
 
+        if self.assume_quads:
+            indices *= 2
+
         if preserve and self.object_bounds is not None:
             indices = jnp.sort(indices)
             object_bounds = jnp.stack(