diff --git a/include/boost/histogram.hpp b/include/boost/histogram.hpp
index 85107ccc..f94d910f 100644
--- a/include/boost/histogram.hpp
+++ b/include/boost/histogram.hpp
@@ -31,7 +31,7 @@
 #include <boost/histogram/literals.hpp>
 #include <boost/histogram/make_histogram.hpp>
 #include <boost/histogram/make_profile.hpp>
-#include <boost/histogram/multi_sum_storage.hpp>
+#include <boost/histogram/multi_storage.hpp>
 #include <boost/histogram/storage_adaptor.hpp>
 #include <boost/histogram/unlimited_storage.hpp>
 
diff --git a/include/boost/histogram/multi_storage.hpp b/include/boost/histogram/multi_storage.hpp
new file mode 100644
index 00000000..b22ef7ef
--- /dev/null
+++ b/include/boost/histogram/multi_storage.hpp
@@ -0,0 +1,112 @@
+// Copyright 2022 Hans Dembinski
+//
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_HISTOGRAM_MULTI_STORAGE_HPP
+#define BOOST_HISTOGRAM_MULTI_STORAGE_HPP
+
+#include <algorithm>
+#include <boost/core/span.hpp>
+#include <boost/histogram/detail/iterator_adaptor.hpp>
+#include <boost/histogram/fwd.hpp>
+#include <memory>
+#include <vector>
+
+namespace boost {
+namespace histogram {
+
+template <class ElementType = double>
+class multi_storage {
+public:
+  using element_type = ElementType;
+
+  struct accumulator : public span<element_type> {
+    using span<element_type>::span;
+
+    void operator()(span<const element_type> values) {
+      if (values.size() != this->size()) throw std::runtime_error("size does not match");
+
+      auto it = this->begin();
+      for (const element_type& v : values) {
+        // TODO make this more flexible, support operator++ and operator()
+        *it++ += v;
+      }
+    }
+  };
+
+  using value_type = std::vector<element_type>;
+  using reference = span<element_type>;
+  using const_reference = span<const element_type>;
+
+  template <class T>
+  struct iterator_base
+      : public detail::iterator_adaptor<iterator_base<T>, T*, span<T>, value_type> {
+    using reference = typename iterator_base::reference;
+    using difference_type = typename iterator_base::difference_type;
+
+    iterator_base(T* ptr, std::size_t nelem)
+        : iterator_base::iterator_adaptor_{ptr}, nelem_{nelem} {}
+    iterator_base(const iterator_base& other)
+        : iterator_base::iterator_adaptor_(other), nelem_{other.nelem_} {}
+    iterator_base& operator=(const iterator_base& other) {
+      if (this != &other) {
+        iterator_base::iterator_adaptor_::operator=(other);
+        nelem_ = other.nelem_;
+      }
+      return *this;
+    }
+
+    iterator_base& operator+=(difference_type n) {
+      iterator_base::iterator_adaptor_::operator+=(n* nelem_);
+      return *this;
+    }
+
+    reference operator*() { return {this->base(), nelem_}; }
+
+    std::size_t nelem_;
+  };
+
+  using iterator = iterator_base<element_type>;
+  using const_iterator = iterator_base<const element_type>;
+
+  static constexpr bool has_threading_support() { return false; }
+
+  multi_storage(const std::size_t nelem) : nelem_{nelem} {}
+
+  std::size_t size() const { return size_; }
+  std::size_t width() const { return nelem_; }
+
+  void reset(std::size_t n) {
+    size_ = n;
+    buffer_.reset(new element_type[n * nelem_]);
+  }
+
+  iterator begin() { return {buffer_.get(), nelem_}; }
+  iterator end() { return {buffer_.get() + size_ * nelem_, nelem_}; }
+
+  const_iterator begin() const { return {buffer_.get(), nelem_}; }
+  const_iterator end() const { return {buffer_.get() + size_ * nelem_, nelem_}; }
+
+  reference operator[](std::size_t i) { return {buffer_.get() + i * nelem_, nelem_}; }
+  const_reference operator[](std::size_t i) const {
+    return {buffer_.get() + i * nelem_, nelem_};
+  }
+
+  template <class T>
+  bool operator==(const multi_storage<T>& other) const {
+    if (size() != other.size()) return false;
+    return std::equal(buffer_._get(), buffer_.get() + size_ * nelem_, other.ptr_.get());
+  }
+
+public:
+  std::size_t size_ = 0;
+  std::size_t nelem_;
+  std::unique_ptr<element_type[]> buffer_;
+};
+
+} // namespace histogram
+} // namespace boost
+
+#endif
\ No newline at end of file
diff --git a/include/boost/histogram/multi_sum_storage.hpp b/include/boost/histogram/multi_sum_storage.hpp
deleted file mode 100644
index d24ca626..00000000
--- a/include/boost/histogram/multi_sum_storage.hpp
+++ /dev/null
@@ -1,108 +0,0 @@
-#ifndef BOOST_HISTOGRAM_MULTI_SUM_STORAGE_HPP
-#define BOOST_HISTOGRAM_MULTI_SUM_STORAGE_HPP
-
-#include <algorithm>
-#include <boost/core/span.hpp>
-#include <boost/histogram.hpp>
-#include <boost/histogram/detail/iterator_adaptor.hpp>
-#include <iostream>
-#include <memory>
-
-namespace boost {
-namespace histogram {
-
-namespace accumulators {
-template <class T>
-struct multi_sum : public boost::span<T> {
-  using boost::span<T>::span;
-
-  void operator()(boost::span<T> values) {
-    if (values.size() != this->size()) throw std::runtime_error("size does not match");
-
-    auto it = this->begin();
-    for (const T& x : values) *it++ += x;
-  }
-};
-} // namespace accumulators
-
-template <class ElementType = double>
-class multi_sum_storage {
-public:
-  template <class T>
-  using multi_sum = accumulators::multi_sum<T>;
-  using element_type = ElementType;
-
-  using value_type = multi_sum<element_type>;
-  using reference = value_type;
-  using const_reference = multi_sum<const element_type>;
-
-  template <class T>
-  struct iterator_base
-      : public detail::iterator_adaptor<iterator_base<T>, std::size_t, multi_sum<T>> {
-    using base_type =
-        detail::iterator_adaptor<iterator_base<T>, std::size_t, multi_sum<T>>;
-
-    iterator_base(T* ptr, std::size_t idx, std::size_t nelem)
-        : base_type{idx}, ptr_{ptr}, nelem_{nelem} {}
-    iterator_base(const iterator_base& other)
-        : base_type(other), ptr_{other.ptr_}, nelem_{other.nelem_} {}
-    iterator_base& operator=(const iterator_base& other) {
-      if (this != &other) {
-        base_type::operator=(other);
-        ptr_ = other.ptr_;
-        nelem_ = other.nelem_;
-      }
-      return *this;
-    }
-
-    decltype(auto) operator*() {
-      return multi_sum<T>{ptr_ + this->base() * nelem_, nelem_};
-    }
-
-    T* ptr_;
-    std::size_t nelem_;
-  };
-
-  using iterator = iterator_base<element_type>;
-  using const_iterator = iterator_base<const element_type>;
-
-  static constexpr bool has_threading_support() { return false; }
-
-  multi_sum_storage(const std::size_t nelem) : nelem_{nelem} {}
-
-  std::size_t size() const { return size_; }
-
-  void reset(std::size_t n) {
-    size_ = n;
-    buffer_.reset(new element_type[n * nelem_]);
-  }
-
-  iterator begin() { return {buffer_.get(), 0, nelem_}; }
-  iterator end() { return {buffer_.get(), size_, nelem_}; }
-
-  const_iterator begin() const { return {buffer_.get(), 0, nelem_}; }
-  const_iterator end() const { return {buffer_.get(), size_, nelem_}; }
-
-  reference operator[](std::size_t i) {
-    return reference{buffer_.get() + i * nelem_, nelem_};
-  }
-  const_reference operator[](std::size_t i) const {
-    return const_reference{buffer_.get() + i * nelem_, nelem_};
-  }
-
-  template <class T>
-  bool operator==(const multi_sum_storage<T>& other) const {
-    if (size() != other.size()) return false;
-    return std::equal(buffer_._get(), buffer_.get() + size_ * nelem_, other.ptr_.get());
-  }
-
-public:
-  std::size_t size_ = 0;
-  std::size_t nelem_;
-  std::unique_ptr<element_type[]> buffer_;
-};
-
-} // namespace histogram
-} // namespace boost
-
-#endif
\ No newline at end of file
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 3340dcee..40b1f79c 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -88,6 +88,7 @@ set_tests_properties(run-boost_histogram-histogram_ostream_ascii_test
   PROPERTIES ENVIRONMENT "LANG=FOO;COLUMNS=20")
 boost_test(TYPE run SOURCES histogram_test.cpp)
 boost_test(TYPE run SOURCES indexed_test.cpp)
+boost_test(TYPE run SOURCES multi_storage_test.cpp)
 boost_test(TYPE run SOURCES storage_adaptor_test.cpp)
 boost_test(TYPE run SOURCES unlimited_storage_test.cpp)
 boost_test(TYPE run SOURCES utility_test.cpp)
diff --git a/test/Jamfile b/test/Jamfile
index 056025d0..d73ca71f 100644
--- a/test/Jamfile
+++ b/test/Jamfile
@@ -84,6 +84,7 @@ alias cxx14 :
     [ run histogram_operators_test.cpp ]
     [ run histogram_test.cpp ]
     [ run indexed_test.cpp ]
+    [ run multi_storage_test.cpp ]
     [ run storage_adaptor_test.cpp ]
     [ run unlimited_storage_test.cpp ]
     [ run utility_test.cpp ]
diff --git a/test/multi_storage_test.cpp b/test/multi_storage_test.cpp
new file mode 100644
index 00000000..9b1028db
--- /dev/null
+++ b/test/multi_storage_test.cpp
@@ -0,0 +1,35 @@
+// Copyright 2022 Hans Dembinski
+//
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt
+// or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/core/lightweight_test.hpp>
+#include <boost/histogram/accumulators/sum.hpp>
+#include <boost/histogram/multi_storage.hpp>
+#include "throw_exception.hpp"
+
+using namespace boost::histogram;
+
+template <class T>
+void test() {
+  using M = multi_storage<T>;
+
+  M m(2);
+
+  BOOST_TEST_EQ(m.width(), 2);
+  BOOST_TEST_EQ(m.size(), 0);
+
+  m.reset(3);
+
+  BOOST_TEST_EQ(m.width(), 2);
+  BOOST_TEST_EQ(m.size(), 3);
+}
+
+int main() {
+
+  test<double>();
+  test<accumulators::sum<double>>();
+
+  return boost::report_errors();
+}
\ No newline at end of file