diff --git a/.appveyor.yml b/.appveyor.yml
index 6214bc72..37d5ee9a 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -6,8 +6,7 @@ shallow_clone: true
 max_jobs: 2
 
 image:
-  - Visual Studio 2017
-  # - Visual Studio 2022 has failing test algorithm_project_test
+  - Visual Studio 2022
 
 branches:
   only:
@@ -30,21 +29,9 @@ install:
   - xcopy /s /e /q %APPVEYOR_BUILD_FOLDER% libs\histogram\
   - python tools\boostdep\depinst\depinst.py -N units -N range -N accumulators --git_args "--depth 5 --jobs 2" histogram
 
-  ## use hdembinski/serialization due to errors in boostorg/serialization
-  # - cd libs/serialization
-  # - git remote add patch https://github.com/HDembinski/serialization.git
-  # - git fetch patch
-  # - git checkout patch/boost_histogram
-  # - cd ../..
-
   # prepare Boost build
-  - cmd /c bootstrap & b2 headers & cd libs\histogram
+  - cmd /c bootstrap & cd libs\histogram
 
 test_script:
-  # on windows
-  - ..\..\b2 %B2_OPTS% cxxstd=latest test//minimal test//serialization
-
-## Uncomment the following to stop VM and enable interactive login.
-## Instructions how to log into the Appveyor VM are automatically printed.
-# on_failure:
-#   - ps: $blockRdp = $true; iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1'))
+  # cxxstd=latest (aka 20) breaks VS 2022 in algorithm_project_test so we use cxxstd=17
+  - ..\..\b2 %B2_OPTS% cxxstd=17 test//minimal test//serialization
diff --git a/.github/workflows/cov.yml b/.github/workflows/cov.yml
index 35c44e5d..affc3342 100644
--- a/.github/workflows/cov.yml
+++ b/.github/workflows/cov.yml
@@ -29,13 +29,6 @@ jobs:
         python tools/boostdep/depinst/depinst.py --git_args "--depth 5 --jobs 3" histogram
         mv -f * $GITHUB_WORKSPACE
 
-        # # use hdembinski/serialization due to frequent errors in boostorg/serialization
-        # pushd libs/serialization
-        # git remote add patch https://github.com/HDembinski/serialization.git
-        # git fetch patch
-        # git checkout patch/boost_histogram
-        # popd
-
     - name: Prepare b2
       run: |
         ./bootstrap.sh
diff --git a/.github/workflows/slow.yml b/.github/workflows/slow.yml
index 9a962eba..a89c9f0a 100644
--- a/.github/workflows/slow.yml
+++ b/.github/workflows/slow.yml
@@ -51,9 +51,7 @@ jobs:
         python tools/boostdep/depinst/depinst.py --git_args "--depth 5 --jobs 3" histogram
         mv -f * $GITHUB_WORKSPACE
     - name: Prepare b2
-      run: |
-        ./bootstrap.sh
-        ./b2 headers
+      run: ./bootstrap.sh
     - name: Test cxxstd=14 exception-handling=off rtti=off
       run: |
         cd libs/histogram
@@ -80,9 +78,7 @@ jobs:
         python tools/boostdep/depinst/depinst.py --git_args "--depth 5 --jobs 3" histogram
         mv -f * $GITHUB_WORKSPACE
     - name: Prepare b2
-      run: |
-        ./bootstrap.sh
-        ./b2 headers
+      run: ./bootstrap.sh
     - name: Test cxxstd=14 (warnings ignored)
       run: |
         cd libs/histogram
@@ -102,9 +98,7 @@ jobs:
         python tools/boostdep/depinst/depinst.py --git_args "--depth 5 --jobs 3" histogram
         mv -f * $GITHUB_WORKSPACE
     - name: Prepare b2
-      run: |
-        ./bootstrap.sh
-        ./b2 headers
+      run: ./bootstrap.sh
     - name: Test cxxstd=20 -O3 -funsafe-math-optimizations
       run: |
         cd libs/histogram
@@ -124,9 +118,7 @@ jobs:
         python tools/boostdep/depinst/depinst.py --git_args "--depth 5 --jobs 3" histogram
         mv -f * $GITHUB_WORKSPACE
     - name: Prepare b2
-      run: |
-        ./bootstrap.sh
-        ./b2 headers
+      run: ./bootstrap.sh
     - name: Test cxxstd=17 ubsan asan
       run: |
         cd libs/histogram
diff --git a/include/boost/histogram/detail/debug.hpp b/include/boost/histogram/detail/debug.hpp
index 952b7557..68402f44 100644
--- a/include/boost/histogram/detail/debug.hpp
+++ b/include/boost/histogram/detail/debug.hpp
@@ -7,7 +7,9 @@
 #ifndef BOOST_HISTOGRAM_DETAIL_DEBUG_HPP
 #define BOOST_HISTOGRAM_DETAIL_DEBUG_HPP
 
-#warning "debug.hpp included"
+#include <boost/config/pragma_message.hpp>
+
+BOOST_PRAGMA_MESSAGE("debug.hpp included")
 
 #include <boost/histogram/detail/type_name.hpp>
 #include <iostream>
diff --git a/test/axis_traits_test.cpp b/test/axis_traits_test.cpp
index 17dc0064..04decded 100644
--- a/test/axis_traits_test.cpp
+++ b/test/axis_traits_test.cpp
@@ -177,14 +177,14 @@ int main() {
       index_type index(ordered_1) { return true; }
     };
     struct ordered_2 {
-      index_type index(int);
+      index_type index(int) { return 0; };
     };
     struct not_ordered_1 {
       constexpr static bool ordered() { return false; }
-      index_type index(int);
+      index_type index(int) { return 0; }
     };
     struct not_ordered_2 {
-      index_type index(not_ordered_2);
+      index_type index(not_ordered_2) { return 0; }
     };
 
     BOOST_TEST_TRAIT_TRUE((traits::is_ordered<ordered_1>));
diff --git a/test/detail_accumulator_traits_test.cpp b/test/detail_accumulator_traits_test.cpp
index bf89ff2d..6a36ba6e 100644
--- a/test/detail_accumulator_traits_test.cpp
+++ b/test/detail_accumulator_traits_test.cpp
@@ -98,8 +98,8 @@ int main() {
   // potentially ambiguous case that mimicks accumulators::weighted_sum
   struct B4 {
     B4(int) {}
-    int operator+=(const weight_type<double>&);
-    int operator+=(const B4&); // *this += 0 succeeds as *this += B4(0)
+    int operator+=(const weight_type<double>&) { return 0; }
+    int operator+=(const B4&) { return 0; } // *this += 0 succeeds as *this += B4(0)
   };
 
   BOOST_TEST(dtl::accumulator_traits<B4>::weight_support);