diff --git a/dev/make-root/rntuple_index_multicluster.C b/dev/make-root/rntuple_index_multicluster.C
new file mode 100644
index 0000000..5f317c3
--- /dev/null
+++ b/dev/make-root/rntuple_index_multicluster.C
@@ -0,0 +1,34 @@
+/* https://root.cern/doc/master/ntpl001__staff_8C.html */
+
+#include <vector>
+
+R__LOAD_LIBRARY(ROOTNTuple)
+#include <ROOT/RField.hxx>
+#include <ROOT/RNTuple.hxx>
+#include <ROOT/RNTupleModel.hxx>
+#include <ROOT/RNTupleWriter.hxx>
+#include <ROOT/RNTupleWriteOptions.hxx>
+#include <ROOT/RRawFile.hxx>
+
+using RNTupleModel = ROOT::Experimental::RNTupleModel;
+using RNTupleWriter = ROOT::Experimental::RNTupleWriter;
+using RNTupleWriteOptions = ROOT::Experimental::RNTupleWriteOptions;
+
+void rntuple_index_multicluster() {
+  auto options = RNTupleWriteOptions();
+  options.SetApproxUnzippedPageSize(512);
+  options.SetApproxZippedClusterSize(1000);
+  options.SetMaxUnzippedClusterSize(1024);
+
+  std::string rootFileName{"test_ntuple_index_multicluster.root"};
+  auto model = RNTupleModel::Create();
+  auto int_vector = model->MakeField<std::vector<int16_t>>("int_vector");
+  auto ntuple =
+      RNTupleWriter::Recreate(std::move(model), "ntuple", rootFileName, options);
+  for(int16_t j=0; j<2; j++){
+      for(int16_t i=0; i<100; i++){
+          *int_vector = {i, static_cast<int16_t>(i+j)};
+          ntuple->Fill();
+      }
+  }
+}
diff --git a/src/skhep_testdata/data/test_ntuple_index_multicluster.root b/src/skhep_testdata/data/test_ntuple_index_multicluster.root
new file mode 100644
index 0000000..43e1418
Binary files /dev/null and b/src/skhep_testdata/data/test_ntuple_index_multicluster.root differ