diff --git a/pytential/qbx/geometry.py b/pytential/qbx/geometry.py
index 4138fbb6902afbfb52ac6b74281861ebb81e1424..374d37d26e0cedbc36a0ceb2e114797a34ee4acc 100644
--- a/pytential/qbx/geometry.py
+++ b/pytential/qbx/geometry.py
@@ -492,8 +492,12 @@ class QBXFMMGeometryData(object):
                         self.coord_dtype)
                 target_radii[:self.ncenters] = self.expansion_radii()
 
-            refine_weights = cl.array.zeros(queue, nparticles, dtype=np.int32)
-            refine_weights[:nsources] = 1
+            # FIXME: https://gitlab.tiker.net/inducer/pytential/issues/72
+            # refine_weights = cl.array.zeros(queue, nparticles, dtype=np.int32)
+            # refine_weights[:nsources] = 1
+            refine_weights = cl.array.empty(queue, nparticles, dtype=np.int32)
+            refine_weights.fill(1)
+
             refine_weights.finish()
 
             tree, _ = code_getter.build_tree(queue,