diff --git a/include/boost/histogram/accumulators/ostream.hpp b/include/boost/histogram/accumulators/ostream.hpp
index 7519bf0e..586d2402 100644
--- a/include/boost/histogram/accumulators/ostream.hpp
+++ b/include/boost/histogram/accumulators/ostream.hpp
@@ -63,7 +63,8 @@ std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>&
 template <class CharT, class Traits, class U>
 std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>& os,
                                               const sum<U>& x) {
-  if (os.width() == 0) return os << "sum(" << x.large() << " + " << x.small() << ")";
+  if (os.width() == 0)
+    return os << "sum(" << x.large_part() << " + " << x.small_part() << ")";
   return detail::handle_nonzero_width(os, x);
 }
 
diff --git a/include/boost/histogram/accumulators/sum.hpp b/include/boost/histogram/accumulators/sum.hpp
index eefdff13..1a7d8442 100644
--- a/include/boost/histogram/accumulators/sum.hpp
+++ b/include/boost/histogram/accumulators/sum.hpp
@@ -43,11 +43,11 @@ class sum {
 
   /// Allow implicit conversion from sum<T>
   template <class T>
-  sum(const sum<T>& s) noexcept : sum(s.large(), s.small()) {}
+  sum(const sum<T>& s) noexcept : sum(s.large_part(), s.small_part()) {}
 
   /// Initialize sum explicitly with large and small parts
-  sum(const_reference large, const_reference small) noexcept
-      : large_(large), small_(small) {}
+  sum(const_reference large_part, const_reference small_part) noexcept
+      : large_(large_part), small_(small_part) {}
 
   /// Increment sum by one
   sum& operator++() noexcept { return operator+=(1); }
@@ -96,10 +96,10 @@ class sum {
   value_type value() const noexcept { return large_ + small_; }
 
   /// Return large part of the sum.
-  const_reference large() const noexcept { return large_; }
+  const_reference large_part() const noexcept { return large_; }
 
   /// Return small part of the sum.
-  const_reference small() const noexcept { return small_; }
+  const_reference small_part() const noexcept { return small_; }
 
   // lossy conversion to value type must be explicit
   explicit operator value_type() const noexcept { return value(); }
@@ -156,6 +156,25 @@ class sum {
 
   // end: extra operators
 
+  // windows.h illegially uses `#define small char` which breaks this now deprecated API
+#if !defined(small)
+
+  /// Return large part of the sum.
+  [[deprecated("use large_part() instead; "
+               "large() will be removed in boost-1.80")]] const_reference
+  large() const noexcept {
+    return large_;
+  }
+
+  /// Return small part of the sum.
+  [[deprecated("use small_part() instead; "
+               "small() will be removed in boost-1.80")]] const_reference
+  small() const noexcept {
+    return small_;
+  }
+
+#endif
+
 private:
   value_type large_{};
   value_type small_{};
diff --git a/include/boost/histogram/algorithm/reduce.hpp b/include/boost/histogram/algorithm/reduce.hpp
index 0646db34..b0f7c7fc 100644
--- a/include/boost/histogram/algorithm/reduce.hpp
+++ b/include/boost/histogram/algorithm/reduce.hpp
@@ -33,7 +33,8 @@ namespace algorithm {
 */
 using reduce_command = detail::reduce_command;
 
-using reduce_option [[deprecated("use reduce_command instead")]] =
+using reduce_option [[deprecated("use reduce_command instead; "
+                                 "reduce_option will be removed in boost-1.80")]] =
     reduce_command; ///< deprecated
 
 /** Shrink command to be used in `reduce`.
diff --git a/include/boost/histogram/axis/traits.hpp b/include/boost/histogram/axis/traits.hpp
index 934969f7..8e75918f 100644
--- a/include/boost/histogram/axis/traits.hpp
+++ b/include/boost/histogram/axis/traits.hpp
@@ -194,7 +194,9 @@ template <class Axis>
 using get_options = decltype(detail::traits_options<Axis>(detail::priority<2>{}));
 
 template <class Axis>
-using static_options [[deprecated("use get_options instead")]] = get_options<Axis>;
+using static_options [[deprecated("use get_options instead; "
+                                  "static_options will be removed in boost-1.80")]] =
+    get_options<Axis>;
 
 #else
 struct get_options;
@@ -223,7 +225,10 @@ template <class Axis>
 using is_inclusive = decltype(detail::traits_is_inclusive<Axis>(detail::priority<1>{}));
 
 template <class Axis>
-using static_is_inclusive [[deprecated("use is_inclusive instead")]] = is_inclusive<Axis>;
+using static_is_inclusive
+    [[deprecated("use is_inclusive instead; "
+                 "static_is_inclusive will be removed in boost-1.80")]] =
+        is_inclusive<Axis>;
 
 #else
 struct is_inclusive;
diff --git a/include/boost/histogram/indexed.hpp b/include/boost/histogram/indexed.hpp
index 47507f0b..3c9e8490 100644
--- a/include/boost/histogram/indexed.hpp
+++ b/include/boost/histogram/indexed.hpp
@@ -64,7 +64,9 @@ class BOOST_ATTRIBUTE_NODISCARD indexed_range {
   using value_type = typename std::iterator_traits<value_iterator>::value_type;
 
   class iterator;
-  using range_iterator [[deprecated("use iterator instead")]] = iterator; ///< deprecated
+  using range_iterator [[deprecated("use iterator instead; "
+                                    "range_iterator will be removed in boost-1.80")]] =
+      iterator; ///< deprecated
 
   /** Lightweight view to access value and index of current cell.
 
@@ -84,7 +86,8 @@ class BOOST_ATTRIBUTE_NODISCARD indexed_range {
 
     public:
       using const_reference = const axis::index_type&;
-      using reference [[deprecated("use const_reference instead")]] =
+      using reference [[deprecated("use const_reference instead; "
+                                   "reference will be removed in boost-1.80")]] =
           const_reference; ///< deprecated
 
       /// implementation detail
diff --git a/test/Jamfile b/test/Jamfile
index 33b50a98..a61e16ce 100644
--- a/test/Jamfile
+++ b/test/Jamfile
@@ -157,11 +157,14 @@ alias libserial :
 # for builds without optional boost dependencies
 alias minimal : cxx14 cxx17 failure threading ;
 
+# for builds with optional boost dependencies
+alias optional_boost : accumulators range units serialization ;
+
 # all tests
-alias all : minimal not_windows odr accumulators range units serialization ;
+alias all : minimal not_windows odr optional_boost ;
 
 # all except "failure", because it is distracting during development
-alias develop : cxx14 cxx17 threading not_windows odr accumulators range units serialization ;
+alias develop : odr cxx14 cxx17 threading not_windows optional_boost ;
 
 explicit minimal ;
 explicit all ;
@@ -176,3 +179,4 @@ explicit range ;
 explicit units ;
 explicit serialization ;
 explicit libserial ;
+explicit optional_boost ;
diff --git a/test/accumulators_sum_test.cpp b/test/accumulators_sum_test.cpp
index 31463e7d..b5708646 100644
--- a/test/accumulators_sum_test.cpp
+++ b/test/accumulators_sum_test.cpp
@@ -26,12 +26,19 @@ int main() {
   ++sum;
   BOOST_TEST_EQ(sum, 1);
   BOOST_TEST_EQ(sum.value(), 1);
-  BOOST_TEST_EQ(sum.large(), 1);
-  BOOST_TEST_EQ(sum.small(), 0);
+  BOOST_TEST_EQ(sum.large_part(), 1);
+  BOOST_TEST_EQ(sum.small_part(), 0);
   BOOST_TEST_EQ(str(sum), "sum(1 + 0)"s);
   BOOST_TEST_EQ(str(sum, 15, false), "     sum(1 + 0)"s);
   BOOST_TEST_EQ(str(sum, 15, true), "sum(1 + 0)     "s);
 
+#include <boost/histogram/detail/ignore_deprecation_warning_begin.hpp>
+
+  BOOST_TEST_EQ(sum.large(), 1);
+  BOOST_TEST_EQ(sum.small(), 0);
+
+#include <boost/histogram/detail/ignore_deprecation_warning_end.hpp>
+
   sum += 1e100;
   BOOST_TEST_EQ(sum, (s_t{1e100, 1}));
   ++sum;
@@ -40,8 +47,8 @@ int main() {
   BOOST_TEST_EQ(sum, (s_t{0, 2}));
   BOOST_TEST_EQ(sum, 2); // correct answer
   BOOST_TEST_EQ(sum.value(), 2);
-  BOOST_TEST_EQ(sum.large(), 0);
-  BOOST_TEST_EQ(sum.small(), 2);
+  BOOST_TEST_EQ(sum.large_part(), 0);
+  BOOST_TEST_EQ(sum.small_part(), 2);
 
   sum = s_t{1e100, 1};
   sum += s_t{1e100, 1};
diff --git a/test/issue_327_test.cpp b/test/issue_327_test.cpp
index 123c2b90..b3fc7c6d 100644
--- a/test/issue_327_test.cpp
+++ b/test/issue_327_test.cpp
@@ -1,3 +1,9 @@
+// Copyright 2021 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.hpp>
 #include <boost/histogram/ostream.hpp>
diff --git a/test/odr_test.cpp b/test/odr_test.cpp
index 3fa08ead..8f2f4822 100644
--- a/test/odr_test.cpp
+++ b/test/odr_test.cpp
@@ -4,6 +4,12 @@
 // (See accompanying file LICENSE_1_0.txt
 // or copy at http://www.boost.org/LICENSE_1_0.txt)
 
+// The header windows.h and possibly others illegially do the following
+#define small char
+// which violates the C++ standard. We make sure here that including our headers work
+// nevertheless by avoiding the preprocessing token `small`. For more details, see
+// https://github.com/boostorg/histogram/issues/342
+
 // include all Boost.Histogram header here; see odr_main_test.cpp for details
 #include <boost/histogram.hpp>
 #include <boost/histogram/ostream.hpp>