diff --git a/src/cooler_file_writer.cpp b/src/cooler_file_writer.cpp
index 6d63e52..1d0e542 100644
--- a/src/cooler_file_writer.cpp
+++ b/src/cooler_file_writer.cpp
@@ -12,6 +12,7 @@
 #include <cstdint>
 #include <filesystem>
 #include <hictk/cooler/cooler.hpp>
+#include <hictk/file.hpp>
 #include <hictk/reference.hpp>
 #include <hictk/tmpdir.hpp>
 #include <hictk/type_traits.hpp>
@@ -113,8 +114,8 @@ void CoolerFileWriter::add_pixels(const nb::object &df) {
       var);
 }
 
-void CoolerFileWriter::finalize([[maybe_unused]] std::string_view log_lvl_str,
-                                std::size_t chunk_size, std::size_t update_freq) {
+hictk::File CoolerFileWriter::finalize(std::string_view log_lvl_str, std::size_t chunk_size,
+                                       std::size_t update_freq) {
   if (_finalized) {
     throw std::runtime_error(
         fmt::format(FMT_STRING("finalize() was already called on file \"{}\""), _path));
@@ -151,6 +152,8 @@ void CoolerFileWriter::finalize([[maybe_unused]] std::string_view log_lvl_str,
   _w.reset();
   std::filesystem::remove(sclr_path);  // NOLINT
   // NOLINTEND(*-unchecked-optional-access)
+
+  return hictk::File{_path.string()};
 }
 
 hictk::cooler::SingleCellFile CoolerFileWriter::create_file(std::string_view path,
@@ -212,7 +215,7 @@ void CoolerFileWriter::bind(nb::module_ &m) {
   // NOLINTBEGIN(*-avoid-magic-numbers)
   writer.def("finalize", &hictkpy::CoolerFileWriter::finalize, nb::arg("log_lvl") = "WARN",
              nb::arg("chunk_size") = 500'000, nb::arg("update_frequency") = 10'000'000,
-             "Write interactions to file.");
+             "Write interactions to file.", nb::rv_policy::move);
   // NOLINTEND(*-avoid-magic-numbers)
 }
 }  // namespace hictkpy
diff --git a/src/file.cpp b/src/file.cpp
index 8606de7..29ba846 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -84,8 +84,9 @@ bool is_cooler(const std::filesystem::path &uri) {
 
 bool is_hic(const std::filesystem::path &uri) { return hictk::hic::utils::is_hic_file(uri); }
 
-static hictkpy::PixelSelector fetch(const hictk::File &f, std::string_view range1,
-                                    std::string_view range2, std::string_view normalization,
+static hictkpy::PixelSelector fetch(const hictk::File &f, std::optional<std::string_view> range1,
+                                    std::optional<std::string_view> range2,
+                                    std::optional<std::string_view> normalization,
                                     std::string_view count_type, bool join,
                                     std::string_view query_type) {
   if (count_type != "float" && count_type != "int") {
@@ -96,15 +97,17 @@ static hictkpy::PixelSelector fetch(const hictk::File &f, std::string_view range
     throw std::runtime_error("query_type should be either UCSC or BED");
   }
 
-  if (normalization != "NONE") {
+  const hictk::balancing::Method normalization_method{normalization.value_or("NONE")};
+
+  if (normalization_method != hictk::balancing::Method::NONE()) {
     count_type = "float";
   }
 
-  if (range1.empty()) {
-    assert(range2.empty());
+  if (!range1.has_value() || range1->empty()) {
+    assert(!range2.has_value() || range2->empty());
     return std::visit(
         [&](const auto &ff) {
-          auto sel = ff.fetch(hictk::balancing::Method{normalization});
+          auto sel = ff.fetch(normalization_method);
           using SelT = decltype(sel);
           return hictkpy::PixelSelector(std::make_shared<const SelT>(std::move(sel)), count_type,
                                         join);
@@ -112,20 +115,21 @@ static hictkpy::PixelSelector fetch(const hictk::File &f, std::string_view range
         f.get());
   }
 
-  if (range2.empty()) {
+  if (!range2.has_value() || range2->empty()) {
     range2 = range1;
   }
 
   const auto query_type_ =
       query_type == "UCSC" ? hictk::GenomicInterval::Type::UCSC : hictk::GenomicInterval::Type::BED;
-  const auto gi1 = hictk::GenomicInterval::parse(f.chromosomes(), std::string{range1}, query_type_);
-  const auto gi2 = hictk::GenomicInterval::parse(f.chromosomes(), std::string{range2}, query_type_);
+  const auto gi1 =
+      hictk::GenomicInterval::parse(f.chromosomes(), std::string{*range1}, query_type_);
+  const auto gi2 =
+      hictk::GenomicInterval::parse(f.chromosomes(), std::string{*range2}, query_type_);
 
   return std::visit(
       [&](const auto &ff) {
-        // Workaround bug fixed in https://github.com/paulsengroup/hictk/pull/158
-        auto sel = ff.fetch(fmt::format(FMT_STRING("{}"), gi1), fmt::format(FMT_STRING("{}"), gi2),
-                            hictk::balancing::Method(normalization));
+        auto sel = ff.fetch(gi1.chrom().name(), gi1.start(), gi1.end(), gi2.chrom().name(),
+                            gi2.start(), gi2.end(), normalization_method);
 
         using SelT = decltype(sel);
         return hictkpy::PixelSelector(std::make_shared<const SelT>(std::move(sel)), count_type,
@@ -307,9 +311,9 @@ void declare_file_class(nb::module_ &m) {
   file.def("attributes", &file::attributes, "Get file attributes as a dictionary.",
            nb::rv_policy::take_ownership);
 
-  file.def("fetch", &file::fetch, nb::keep_alive<0, 1>(), nb::arg("range1") = "",
-           nb::arg("range2") = "", nb::arg("normalization") = "NONE", nb::arg("count_type") = "int",
-           nb::arg("join") = false, nb::arg("query_type") = "UCSC",
+  file.def("fetch", &file::fetch, nb::keep_alive<0, 1>(), nb::arg("range1") = nb::none(),
+           nb::arg("range2") = nb::none(), nb::arg("normalization") = nb::none(),
+           nb::arg("count_type") = "int", nb::arg("join") = false, nb::arg("query_type") = "UCSC",
            "Fetch interactions overlapping a region of interest.", nb::rv_policy::move);
 
   file.def("avail_normalizations", &file::avail_normalizations,
diff --git a/src/hic_file_writer.cpp b/src/hic_file_writer.cpp
index f25363d..a5eadea 100644
--- a/src/hic_file_writer.cpp
+++ b/src/hic_file_writer.cpp
@@ -10,6 +10,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <filesystem>
+#include <hictk/file.hpp>
 #include <hictk/reference.hpp>
 #include <hictk/tmpdir.hpp>
 #include <stdexcept>
@@ -73,7 +74,7 @@ HiCFileWriter::HiCFileWriter(const std::filesystem::path &path_, const hictkpy::
                     assembly, n_threads, chunk_size, tmpdir, compression_lvl,
                     skip_all_vs_all_matrix) {}
 
-void HiCFileWriter::finalize([[maybe_unused]] std::string_view log_lvl_str) {
+hictk::File HiCFileWriter::finalize([[maybe_unused]] std::string_view log_lvl_str) {
   if (_finalized) {
     throw std::runtime_error(
         fmt::format(FMT_STRING("finalize() was already called on file \"{}\""), _w.path()));
@@ -93,14 +94,25 @@ void HiCFileWriter::finalize([[maybe_unused]] std::string_view log_lvl_str) {
   }
   SPDLOG_INFO(FMT_STRING("successfully finalized \"{}\"!"), _w.path());
   spdlog::default_logger()->set_level(previous_lvl);
+
+  return hictk::File{std::string{_w.path()}, _w.resolutions().front()};
 }
 
 std::filesystem::path HiCFileWriter::path() const noexcept {
   return std::filesystem::path{_w.path()};
 }
 
-const std::vector<std::uint32_t> &HiCFileWriter::resolutions() const noexcept {
-  return _w.resolutions();
+auto HiCFileWriter::resolutions() const {
+  using WeightVector = nb::ndarray<nb::numpy, nb::shape<-1>, nb::c_contig, std::uint32_t>;
+
+  // NOLINTNEXTLINE
+  auto *resolutions_ptr = new std::vector<std::uint32_t>(_w.resolutions());
+
+  auto capsule = nb::capsule(resolutions_ptr, [](void *vect_ptr) noexcept {
+    delete reinterpret_cast<std::vector<std::uint32_t> *>(vect_ptr);  // NOLINT
+  });
+
+  return WeightVector{resolutions_ptr->data(), {resolutions_ptr->size()}, capsule};
 }
 
 const hictk::Reference &HiCFileWriter::chromosomes() const { return _w.chromosomes(); }
@@ -171,7 +183,7 @@ void HiCFileWriter::bind(nb::module_ &m) {
 
   writer.def("path", &hictkpy::HiCFileWriter::path, "Get the file path.", nb::rv_policy::move);
   writer.def("resolutions", &hictkpy::HiCFileWriter::resolutions,
-             "Get the list of resolutions in bp.", nb::rv_policy::move);
+             "Get the list of resolutions in bp.", nb::rv_policy::take_ownership);
   writer.def("chromosomes", &get_chromosomes_from_object<hictkpy::HiCFileWriter>,
              nb::arg("include_ALL") = false,
              "Get chromosomes sizes as a dictionary mapping names to sizes.",
@@ -185,7 +197,7 @@ void HiCFileWriter::bind(nb::module_ &m) {
              "either with columns=[bin1_id, bin2_id, count] or with columns=[chrom1, start1, end1, "
              "chrom2, start2, end2, count].");
   writer.def("finalize", &hictkpy::HiCFileWriter::finalize, nb::arg("log_lvl") = "WARN",
-             "Write interactions to file.");
+             "Write interactions to file.", nb::rv_policy::move);
 }
 
 }  // namespace hictkpy
diff --git a/src/include/hictkpy/cooler_file_writer.hpp b/src/include/hictkpy/cooler_file_writer.hpp
index 456da33..ec90b4b 100644
--- a/src/include/hictkpy/cooler_file_writer.hpp
+++ b/src/include/hictkpy/cooler_file_writer.hpp
@@ -7,6 +7,7 @@
 #include <cstdint>
 #include <filesystem>
 #include <hictk/cooler/singlecell_cooler.hpp>
+#include <hictk/file.hpp>
 #include <hictk/reference.hpp>
 #include <hictk/tmpdir.hpp>
 #include <optional>
@@ -43,7 +44,8 @@ class CoolerFileWriter {
 
   void add_pixels(const nanobind::object& df);
 
-  void finalize(std::string_view log_lvl_str, std::size_t chunk_size, std::size_t update_frequency);
+  [[nodiscard]] hictk::File finalize(std::string_view log_lvl_str, std::size_t chunk_size,
+                                     std::size_t update_frequency);
 
   [[nodiscard]] std::string repr() const;
   static void bind(nanobind::module_& m);
diff --git a/src/include/hictkpy/dynamic_1d_array.hpp b/src/include/hictkpy/dynamic_1d_array.hpp
deleted file mode 100644
index e592e89..0000000
--- a/src/include/hictkpy/dynamic_1d_array.hpp
+++ /dev/null
@@ -1,43 +0,0 @@
-// Copyright (C) 2024 Roberto Rossini <roberros@uio.no>
-//
-// SPDX-License-Identifier: MIT
-
-#pragma once
-
-#include <cstddef>
-#include <cstdint>
-#include <type_traits>
-
-#include "hictkpy/nanobind.hpp"
-
-namespace hictkpy {
-
-template <typename T>
-struct Dynamic1DA {
- private:
-  using BufferT = nanobind::ndarray<nanobind::numpy, nanobind::shape<-1>, T>;
-  using VectorT = decltype(std::declval<BufferT>().view());
-  nanobind::object _dtype{};
-  nanobind::object _np_array{};
-  BufferT _buff{};
-  VectorT _vector{};
-
-  std::int64_t _size{};
-  std::int64_t _capacity{};
-
- public:
-  explicit Dynamic1DA(std::size_t size_ = 1000);
-  void push_back(T x);
-  void emplace_back(T &&x);
-  void resize(std::int64_t new_size);
-  void grow();
-  void shrink_to_fit();
-  [[nodiscard]] auto operator()() -> BufferT;
-
- private:
-  [[nodiscard]] static nanobind::object np();
-};
-
-}  // namespace hictkpy
-
-#include "./impl/dynamic_1d_array_impl.hpp"
diff --git a/src/include/hictkpy/hic_file_writer.hpp b/src/include/hictkpy/hic_file_writer.hpp
index ddb70c2..1041b72 100644
--- a/src/include/hictkpy/hic_file_writer.hpp
+++ b/src/include/hictkpy/hic_file_writer.hpp
@@ -7,6 +7,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <filesystem>
+#include <hictk/file.hpp>
 #include <hictk/hic/file_writer.hpp>
 #include <hictk/reference.hpp>
 #include <hictk/tmpdir.hpp>
@@ -40,14 +41,14 @@ class HiCFileWriter {
                 bool skip_all_vs_all_matrix);
 
   [[nodiscard]] std::filesystem::path path() const noexcept;
-  [[nodiscard]] const std::vector<std::uint32_t>& resolutions() const noexcept;
+  [[nodiscard]] auto resolutions() const;
 
   [[nodiscard]] const hictk::Reference& chromosomes() const;
   [[nodiscard]] hictkpy::BinTable bins(std::uint32_t resolution) const;
 
   void add_pixels(const nanobind::object& df);
 
-  void finalize(std::string_view log_lvl_str);
+  [[nodiscard]] hictk::File finalize(std::string_view log_lvl_str);
 
   [[nodiscard]] std::string repr() const;
 
diff --git a/src/include/hictkpy/impl/dynamic_1d_array_impl.hpp b/src/include/hictkpy/impl/dynamic_1d_array_impl.hpp
deleted file mode 100644
index ea83905..0000000
--- a/src/include/hictkpy/impl/dynamic_1d_array_impl.hpp
+++ /dev/null
@@ -1,81 +0,0 @@
-// Copyright (C) 2024 Roberto Rossini <roberros@uio.no>
-//
-// SPDX-License-Identifier: MIT
-
-#pragma once
-
-#include <algorithm>
-#include <cstddef>
-#include <cstdint>
-#include <utility>
-
-#include "hictkpy/common.hpp"
-#include "hictkpy/nanobind.hpp"
-
-namespace hictkpy {
-
-template <typename T>
-inline Dynamic1DA<T>::Dynamic1DA(std::size_t size_)
-    : _dtype(np().attr("dtype")(map_type_to_dtype<T>())),
-      _np_array(
-          np().attr("empty")(static_cast<std::int64_t>(size_), nanobind::arg("dtype") = _dtype)),
-      _buff(nanobind::cast<BufferT>(_np_array)),
-      _vector(_buff.view()),
-      _capacity(static_cast<std::int64_t>(size_)) {}
-
-template <typename T>
-inline void Dynamic1DA<T>::push_back(T x) {
-  if (_capacity == _size) {
-    grow();
-  }
-  _vector(_size++) = x;
-}
-
-template <typename T>
-inline void Dynamic1DA<T>::emplace_back(T &&x) {
-  if (_capacity == _size) {
-    grow();
-  }
-  _vector(_size++) = std::move(x);
-}
-
-template <typename T>
-inline void Dynamic1DA<T>::resize(std::int64_t new_size) {
-  if (_capacity == new_size) {
-    return;
-  }
-  auto new_array = np().attr("empty")(new_size, nanobind::arg("dtype") = _dtype);
-  auto new_buff = nanobind::cast<BufferT>(new_array);
-  auto new_vector = new_buff.view();
-
-  _capacity = new_size;
-  _size = std::min(_capacity, _size);
-  std::copy(_vector.data(), _vector.data() + static_cast<std::size_t>(_size), new_vector.data());
-
-  std::swap(new_array, _np_array);
-  std::swap(new_buff, _buff);
-  std::swap(new_vector, _vector);
-}
-
-template <typename T>
-inline void Dynamic1DA<T>::grow() {
-  resize(static_cast<std::int64_t>(_buff.size() * 2));
-}
-
-template <typename T>
-inline void Dynamic1DA<T>::shrink_to_fit() {
-  resize(_size);
-}
-
-template <typename T>
-[[nodiscard]] auto Dynamic1DA<T>::operator()() -> BufferT {
-  shrink_to_fit();
-  return _buff;
-}
-
-template <typename T>
-[[nodiscard]] nanobind::object Dynamic1DA<T>::np() {
-  return nanobind::module_::import_("numpy");
-}
-
-}  // namespace hictkpy
diff --git a/src/multires_file.cpp b/src/multires_file.cpp
index 15dace7..f8b7121 100644
--- a/src/multires_file.cpp
+++ b/src/multires_file.cpp
@@ -9,6 +9,7 @@
 #include <hictk/cooler/validation.hpp>
 #include <hictk/multires_file.hpp>
 #include <string>
+#include <vector>
 
 #include "hictkpy/nanobind.hpp"
 #include "hictkpy/reference.hpp"
@@ -27,6 +28,19 @@ static std::string repr(const hictk::MultiResFile& mrf) {
 
 static std::filesystem::path get_path(const hictk::MultiResFile& mrf) { return mrf.path(); }
 
+[[nodiscard]] static auto get_resolutions(const hictk::MultiResFile& f) {
+  using WeightVector = nb::ndarray<nb::numpy, nb::shape<-1>, nb::c_contig, std::uint32_t>;
+
+  // NOLINTNEXTLINE
+  auto* resolutions_ptr = new std::vector<std::uint32_t>(f.resolutions());
+
+  auto capsule = nb::capsule(resolutions_ptr, [](void* vect_ptr) noexcept {
+    delete reinterpret_cast<std::vector<std::uint32_t>*>(vect_ptr);  // NOLINT
+  });
+
+  return WeightVector{resolutions_ptr->data(), {resolutions_ptr->size()}, capsule};
+}
+
 static nb::dict get_attrs(const hictk::hic::File& hf) {
   nb::dict py_attrs;
 
@@ -59,7 +73,7 @@ static nb::dict get_attrs(const hictk::cooler::MultiResFile& mclr) {
 static nb::dict attributes(const hictk::MultiResFile& f) {
   auto attrs = f.is_hic() ? get_attrs(f.open(f.resolutions().front()).get<hictk::hic::File>())
                           : get_attrs(hictk::cooler::MultiResFile{f.path()});
-  attrs["resolutions"] = f.resolutions();
+  attrs["resolutions"] = get_resolutions(f);
 
   return attrs;
 }
@@ -84,8 +98,8 @@ void declare_multires_file_class(nb::module_& m) {
                 nb::arg("include_ALL") = false,
                 "Get chromosomes sizes as a dictionary mapping names to sizes.",
                 nb::rv_policy::take_ownership);
-  mres_file.def("resolutions", &hictk::MultiResFile::resolutions,
-                "Get the list of available resolutions.", nb::rv_policy::copy);
+  mres_file.def("resolutions", &get_resolutions, "Get the list of available resolutions.",
+                nb::rv_policy::take_ownership);
   mres_file.def("attributes", &multires_file::attributes, "Get file attributes as a dictionary.",
                 nb::rv_policy::take_ownership);
   mres_file.def("__getitem__", &hictk::MultiResFile::open,
diff --git a/test/test_file_creation_cool.py b/test/test_file_creation_cool.py
index 4a77605..1685326 100644
--- a/test/test_file_creation_cool.py
+++ b/test/test_file_creation_cool.py
@@ -62,7 +62,7 @@ def test_file_creation_thin_pixel(self, file, resolution, tmpdir):
             end = start + chunk_size
             w.add_pixels(df[start:end])
 
-        w.finalize("info", 100_000, 100_000)
+        f = w.finalize("info", 100_000, 100_000)
         with pytest.raises(Exception):
             w.add_pixels(df)
         with pytest.raises(Exception):
@@ -71,7 +71,6 @@ def test_file_creation_thin_pixel(self, file, resolution, tmpdir):
         del w
         gc.collect()
 
-        f = hictkpy.File(path, resolution)
         assert f.fetch().sum() == expected_sum
 
     def test_file_creation(self, file, resolution, tmpdir):
@@ -90,7 +89,7 @@ def test_file_creation(self, file, resolution, tmpdir):
             end = start + chunk_size
             w.add_pixels(df[start:end])
 
-        w.finalize("info", 100_000, 100_000)
+        f = w.finalize("info", 100_000, 100_000)
         with pytest.raises(Exception):
             w.add_pixels(df)
         with pytest.raises(Exception):
@@ -99,7 +98,6 @@ def test_file_creation(self, file, resolution, tmpdir):
         del w
         gc.collect()
 
-        f = hictkpy.File(path, resolution)
         assert f.fetch().sum() == expected_sum
 
     def test_file_creation_bin_table(self, file, resolution, tmpdir):
@@ -116,7 +114,7 @@ def test_file_creation_bin_table(self, file, resolution, tmpdir):
             end = start + chunk_size
             w.add_pixels(df[start:end])
 
-        w.finalize("info", 100_000, 100_000)
+        f = w.finalize("info", 100_000, 100_000)
         with pytest.raises(Exception):
             w.add_pixels(df)
         with pytest.raises(Exception):
@@ -125,7 +123,6 @@ def test_file_creation_bin_table(self, file, resolution, tmpdir):
         del w
         gc.collect()
 
-        f = hictkpy.File(path, resolution)
         assert f.fetch().sum() == expected_sum
 
     def test_file_creation_float_counts(self, file, resolution, tmpdir):
@@ -145,7 +142,7 @@ def test_file_creation_float_counts(self, file, resolution, tmpdir):
             end = start + chunk_size
             w.add_pixels(df[start:end])
 
-        w.finalize("info", 100_000, 100_000)
+        f = w.finalize("info", 100_000, 100_000)
         with pytest.raises(Exception):
             w.add_pixels(df)
         with pytest.raises(Exception):
@@ -154,5 +151,4 @@ def test_file_creation_float_counts(self, file, resolution, tmpdir):
         del w
         gc.collect()
 
-        f = hictkpy.File(path, resolution)
         assert pytest.approx(f.fetch(count_type="float").sum()) == expected_sum
diff --git a/test/test_file_creation_hic.py b/test/test_file_creation_hic.py
index dc03e73..347ef20 100644
--- a/test/test_file_creation_hic.py
+++ b/test/test_file_creation_hic.py
@@ -61,7 +61,7 @@ def test_file_creation_thin_pixel(self, file, resolution, tmpdir):
             end = start + chunk_size
             w.add_pixels(df[start:end])
 
-        w.finalize()
+        f = w.finalize()
         with pytest.raises(Exception):
             w.add_pixels(df)
         with pytest.raises(Exception):
@@ -70,7 +70,6 @@ def test_file_creation_thin_pixel(self, file, resolution, tmpdir):
         del w
         gc.collect()
 
-        f = hictkpy.File(path, resolution)
         assert f.fetch().sum() == expected_sum
 
     def test_file_creation(self, file, resolution, tmpdir):
@@ -89,7 +88,7 @@ def test_file_creation(self, file, resolution, tmpdir):
             end = start + chunk_size
             w.add_pixels(df[start:end])
 
-        w.finalize()
+        f = w.finalize()
         with pytest.raises(Exception):
             w.add_pixels(df)
         with pytest.raises(Exception):
@@ -98,7 +97,6 @@ def test_file_creation(self, file, resolution, tmpdir):
         del w
         gc.collect()
 
-        f = hictkpy.File(path, resolution)
         assert f.fetch().sum() == expected_sum
 
     def test_file_creation_bin_table(self, file, resolution, tmpdir):
@@ -120,7 +118,7 @@ def test_file_creation_bin_table(self, file, resolution, tmpdir):
             end = start + chunk_size
             w.add_pixels(df[start:end])
 
-        w.finalize()
+        f = w.finalize()
         with pytest.raises(Exception):
             w.add_pixels(df)
         with pytest.raises(Exception):
@@ -129,5 +127,4 @@ def test_file_creation_bin_table(self, file, resolution, tmpdir):
         del w
         gc.collect()
 
-        f = hictkpy.File(path, resolution)
         assert f.fetch().sum() == expected_sum
diff --git a/test/test_multires_file_accessors.py b/test/test_multires_file_accessors.py
index 6255afb..4e1e1c5 100644
--- a/test/test_multires_file_accessors.py
+++ b/test/test_multires_file_accessors.py
@@ -32,16 +32,16 @@ def test_accessors(self, file, format):
 
         if f.is_hic():
             resolutions = [100_000]
-            assert f.resolutions() == resolutions
+            assert (f.resolutions() == resolutions).all()
             assert f.attributes()["format"] == "HIC"
             assert f.attributes()["format-version"] == 9
-            assert f.attributes()["resolutions"] == resolutions
+            assert (f.attributes()["resolutions"] == resolutions).all()
         else:
             resolutions = [100_000, 1_000_000]
-            assert f.resolutions() == resolutions
+            assert (f.resolutions() == resolutions).all()
             assert f.attributes()["format"] == "HDF5::MCOOL"
             assert f.attributes()["format-version"] == 2
-            assert f.attributes()["resolutions"] == resolutions
+            assert (f.attributes()["resolutions"] == resolutions).all()
 
         assert f[100_000].resolution() == 100_000