diff --git a/test_data/cluster/DCLU_48 b/test_data/cluster/DCLU_48
index 6a4dba14577f0ec92d13346bf036cf1557860a41..0a6975bb9153a9fb84774ad3d43bbb880eb38dfe 100644
--- a/test_data/cluster/DCLU_48
+++ b/test_data/cluster/DCLU_48
@@ -51,3 +51,5 @@
  0.00D01  0.00D00  0.00D01  0.00D00  0.00D01  0.00D01
  1
 0
+# COMMENT: next line enables iterative refinement at run-time
+USE_REFINEMENT=1