diff --git a/.github/setenv.sh b/.github/setenv.sh
index 3eb65a108..3ba6c611d 100644
--- a/.github/setenv.sh
+++ b/.github/setenv.sh
@@ -13,6 +13,8 @@ function c4_show_info()
     echo "PROJ_PFX_TARGET=$PROJ_PFX_TARGET"
     echo "PROJ_PFX_CMAKE=$PROJ_PFX_CMAKE"
     echo "CMAKE_FLAGS=$CMAKE_FLAGS"
+    echo "CMAKE_C_FLAGS=$CMAKE_C_FLAGS"
+    echo "CMAKE_CXX_FLAGS=$CMAKE_CXX_FLAGS"
     echo "NUM_JOBS_BUILD=$NUM_JOBS_BUILD"
     echo "GITHUB_WORKSPACE=$GITHUB_WORKSPACE"
     pwd
@@ -304,7 +306,7 @@ function c4_cfg_test()
                   -G 'Visual Studio 17 2022' -A $(_c4vsarchtype $id) \
                   $(_c4_add_ehsc_to_vs_arm32 $id) \
                   -DCMAKE_BUILD_TYPE=$BT $CMFLAGS \
-                  -DCMAKE_C_FLAGS=" $CFLAGS" -DCMAKE_CXX_FLAGS=" $CXXFLAGS"
+                  -DCMAKE_C_FLAGS=" $CFLAGS $CMAKE_C_FLAGS" -DCMAKE_CXX_FLAGS=" $CXXFLAGS $CMAKE_CXX_FLAGS"
             ;;
         vs2019)
             cmake -S $PROJ_DIR -B $build_dir -DCMAKE_INSTALL_PREFIX="$install_dir" \
diff --git a/.github/workflows/clang.yml b/.github/workflows/clang.yml
index 911163d65..bc3f19f5e 100644
--- a/.github/workflows/clang.yml
+++ b/.github/workflows/clang.yml
@@ -192,7 +192,58 @@ jobs:
           - {std: 11, cxx: "4.0", bt: Release, vg: on, img: ubuntu18.04}
           - {std: 11, cxx: "3.9", bt: Debug  , vg: on, img: ubuntu18.04}
           - {std: 11, cxx: "3.9", bt: Release, vg: on, img: ubuntu18.04}
-    env: {STD: "${{matrix.std}}", CXX_: "clang++-${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    env: {
+      STD: "${{matrix.std}}", CXX_: "clang++-${{matrix.cxx}}", BT: "${{matrix.bt}}",
+      BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}",
+      SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"
+      }
+    steps:
+      - {name: checkout, uses: actions/checkout@v3, with: {submodules: recursive}}
+      - run: git config --system --add safe.directory '*'  # needed for running in the docker image. see https://github.com/actions/checkout/issues/1169
+      - run: c4core-install $CXX_
+      - {name: show info, run: source .github/setenv.sh && c4_show_info}
+      - name: shared64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared64
+      - {name: shared64-build, run: source .github/setenv.sh && c4_build_test shared64}
+      - {name: shared64-run, run: source .github/setenv.sh && c4_run_test shared64}
+      - {name: shared64-pack, run: source .github/setenv.sh && c4_package shared64}
+      - name: static64-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static64
+      - {name: static64-build, run: source .github/setenv.sh && c4_build_test static64}
+      - {name: static64-run, run: source .github/setenv.sh && c4_run_test static64}
+      - {name: static64-pack, run: source .github/setenv.sh && c4_package static64}
+      - name: static32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test static32
+      - {name: static32-build, run: source .github/setenv.sh && c4_build_test static32}
+      - {name: static32-run, run: source .github/setenv.sh && c4_run_test static32}
+      - {name: static32-pack, run: source .github/setenv.sh && c4_package static32}
+      - name: shared32-configure---------------------------------------------------
+        run: source .github/setenv.sh && c4_cfg_test shared32
+      - {name: shared32-build, run: source .github/setenv.sh && c4_build_test shared32}
+      - {name: shared32-run, run: source .github/setenv.sh && c4_run_test shared32}
+      - {name: shared32-pack, run: source .github/setenv.sh && c4_package shared32}
+
+  #----------------------------------------------------------------------------
+  clang_fuzz:
+    name: clang_fuzz/${{matrix.cxx}}/c++${{matrix.std}}/${{matrix.bt}}/vg${{matrix.vg}}
+    continue-on-error: true
+    if: always()  # https://stackoverflow.com/questions/62045967/github-actions-is-there-a-way-to-continue-on-error-while-still-getting-correct
+    runs-on: ubuntu-latest
+    container: ghcr.io/biojppm/c4core/${{matrix.img}}:latest  # use the docker image
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - {std: 11, cxx: "16" , bt: fuzz   , vg: on, img: ubuntu18.04}
+          - {std: 11, cxx: "16" , bt: Debug  , vg: on, img: ubuntu18.04}
+          - {std: 11, cxx: "16" , bt: Release, vg: on, img: ubuntu18.04}
+    env: {
+      CMAKE_CXX_FLAGS: "-g -O0 -fsanitize=address,undefined",
+      CMAKE_FLAGS: "-DRYML_TEST_FUZZ=ON -DRYML_FUZZ_LIBFUZZER_MERGE=ON",
+      STD: "${{matrix.std}}", CXX_: "clang++-${{matrix.cxx}}", BT: "${{matrix.bt}}",
+      BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}",xs SAN: "${{matrix.san}}",
+      LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"
+      }
     steps:
       - {name: checkout, uses: actions/checkout@v3, with: {submodules: recursive}}
       - run: git config --system --add safe.directory '*'  # needed for running in the docker image. see https://github.com/actions/checkout/issues/1169
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index d2e7872c3..f233d2824 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -46,7 +46,7 @@ jobs:
     env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}",
           BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}",
           LINT: "${{matrix.lint}}", OS: "${{matrix.os}}",
-          CMAKE_FLAGS: "${{matrix.cmk}}",
+          CMAKE_FLAGS: "${{matrix.cmk}} -DRYML_TEST_FUZZ=ON",
           CODECOV_TOKEN: "${{secrets.CODECOV_TOKEN}}",
           COVERALLS_REPO_TOKEN: "${{secrets.COVERALLS_REPO_TOKEN}}",
           # coveralls disabled: https://github.com/lemurheavy/coveralls-public/issues/1665
diff --git a/.github/workflows/gcc.yml b/.github/workflows/gcc.yml
index 2a16edb27..d92b80a18 100644
--- a/.github/workflows/gcc.yml
+++ b/.github/workflows/gcc.yml
@@ -44,7 +44,10 @@ jobs:
           - {std: 11, cxx: g++-5  , bt: Release, bitlinks: shared64 static32}
           - {std: 11, cxx: g++-4.8, bt: Debug  , bitlinks: shared64 static32}
           - {std: 11, cxx: g++-4.8, bt: Release, bitlinks: shared64 static32}
-    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    env: {
+      STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}",
+      BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"
+      }
     steps:
       - {name: checkout, uses: actions/checkout@v3, with: {submodules: recursive}}
       - run: git config --system --add safe.directory '*'  # needed for running in the docker image. see https://github.com/actions/checkout/issues/1169
@@ -134,7 +137,13 @@ jobs:
           - {std: 11, cxx: g++-7      , bt: Release, bitlinks: shared64 static32}
           - {std: 20, cxx: g++-10     , bt: Debug  , bitlinks: shared64 static32}
           - {std: 20, cxx: g++-10     , bt: Release, bitlinks: shared64 static32}
-    env: {CXXFLAGS: "-fno-exceptions -fno-rtti", STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    env: {
+      CXXFLAGS: "-fno-exceptions -fno-rtti",
+      CMAKE_FLAGS: "-DRYML_TEST_FUZZ=ON",
+      STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}",
+      BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}",
+      SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"
+      }
     steps:
       - {name: checkout, uses: actions/checkout@v3, with: {submodules: recursive}}
       - run: git config --system --add safe.directory '*'  # needed for running in the docker image. see https://github.com/actions/checkout/issues/1169
@@ -200,7 +209,12 @@ jobs:
           - {std: 11, cxx: g++-4.9, bt: Release, img: ubuntu18.04}
           - {std: 11, cxx: g++-4.8, bt: Debug  , img: ubuntu18.04}
           - {std: 11, cxx: g++-4.8, bt: Release, img: ubuntu18.04}
-    env: {STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}", BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}", SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"}
+    env: {
+      CMAKE_FLAGS: "-DRYML_TEST_FUZZ=ON",
+      STD: "${{matrix.std}}", CXX_: "${{matrix.cxx}}", BT: "${{matrix.bt}}",
+      BITLINKS: "${{matrix.bitlinks}}", VG: "${{matrix.vg}}",
+      SAN: "${{matrix.san}}", LINT: "${{matrix.lint}}", OS: "${{matrix.os}}"
+      }
     steps:
       - {name: checkout, uses: actions/checkout@v3, with: {submodules: recursive}}
       - run: git config --system --add safe.directory '*'  # needed for running in the docker image. see https://github.com/actions/checkout/issues/1169
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 7f8d4f0b5..1b5d870b5 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -269,7 +269,13 @@ endif(RYML_TEST_SUITE)
 #------------------------------------------------------------------------------
 
 string(TOUPPER "${CMAKE_BUILD_TYPE}" upper_build_type)
-if((upper_build_type STREQUAL FUZZ) OR (upper_build_type STREQUAL COVERAGE))
+if(upper_build_type STREQUAL FUZZ)
+    option(RYML_TEST_FUZZ "Enable fuzz tests" ON)
+else()
+    option(RYML_TEST_FUZZ "Enable fuzz tests" OFF)
+endif()
+
+if(RYML_TEST_FUZZ)
     c4_download_remote_proj(rapidyaml-data rapidyaml_data_dir
         GIT_REPOSITORY https://github.com/biojppm/rapidyaml-data
         GIT_TAG master)
@@ -288,24 +294,21 @@ if((upper_build_type STREQUAL FUZZ) OR (upper_build_type STREQUAL COVERAGE))
     function(ryml_add_fuzz_test name)
         c4_add_executable(ryml-test-fuzz-${name}
             SOURCES
-                test_fuzz/test_fuzz_common.hpp
-                test_fuzz/test_fuzz_${name}.cpp
-                test_fuzz/test_fuzz_main.cpp
+            test_fuzz/test_fuzz_common.hpp
+            test_fuzz/test_fuzz_${name}.cpp
+            test_fuzz/test_fuzz_main.cpp
             ${ARGN}
             INC_DIRS ${CMAKE_CURRENT_LIST_DIR}
             LIBS ryml c4fs
             FOLDER test/fuzz)
         function(ryml_add_fuzz_test_file name_ dir file)
             string(REPLACE "/" "_" fuzz_name "${file}")
-            #add_test(NAME ryml-test-fuzz-${name_}-${fuzz_name}
-            #    COMMAND $<TARGET_FILE:ryml-test-fuzz-${name_}> ${dir}/${file})
+            add_test(NAME ryml-test-fuzz-${name_}-${fuzz_name}
+                COMMAND $<TARGET_FILE:ryml-test-fuzz-${name_}> ${dir}/${file})
         endfunction()
         foreach(fuzz_file ${fuzz_files})
             ryml_add_fuzz_test_file(${name} ${corpus_artifacts_dir} ${fuzz_file})
         endforeach()
-        foreach(fuzz_file ${suite_files})
-            ryml_add_fuzz_test_file(${name} ${corpus_suite_dir} ${fuzz_file})
-        endforeach()
         if(RYML_DBG)
             target_compile_definitions(ryml-test-fuzz-${name} PUBLIC RYML_DBG)
         endif()
@@ -329,7 +332,7 @@ if((upper_build_type STREQUAL FUZZ) OR (upper_build_type STREQUAL COVERAGE))
     #
     #
     # libfuzzer: https://llvm.org/docs/LibFuzzer.html
-    if((upper_build_type STREQUAL FUZZ) AND ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang"))
+    if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
         option(RYML_FUZZ_LIBFUZZER_MERGE OFF "merge fuzz corpus")
         option(RYML_FUZZ_LIBFUZZER_MERGE_RESUME ON "resume merge")
         option(RYML_FUZZ_LIBFUZZER_DICT ON "use a yaml dict")
diff --git a/test/test_fuzz/test_fuzz_common.hpp b/test/test_fuzz/test_fuzz_common.hpp
index f2c45462f..d098003da 100644
--- a/test/test_fuzz/test_fuzz_common.hpp
+++ b/test/test_fuzz/test_fuzz_common.hpp
@@ -60,7 +60,7 @@ inline C4_NORETURN void errcallback(const char *msg, size_t msg_len, c4::yml::Lo
         jmp_msg.assign(msg, msg_len);
         std::longjmp(jmp_env, 1);
     );
-};
+}
 
 inline c4::yml::Callbacks create_custom_callbacks()
 {
diff --git a/test/test_fuzz/test_fuzz_events.cpp b/test/test_fuzz/test_fuzz_events.cpp
index 20c668273..a857a2fe6 100644
--- a/test/test_fuzz/test_fuzz_events.cpp
+++ b/test/test_fuzz/test_fuzz_events.cpp
@@ -3,7 +3,7 @@
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *str, size_t len)
 {
-    static std::atomic_uint32_t case_number{0};
+    static std::atomic<uint32_t> case_number{0};
     c4::csubstr src = {reinterpret_cast<const char*>(str), len};
     return c4::yml::fuzztest_yaml_events(case_number++, src);
 }
diff --git a/test/test_fuzz/test_fuzz_parse_emit.cpp b/test/test_fuzz/test_fuzz_parse_emit.cpp
index 08f62cad5..dc4c08057 100644
--- a/test/test_fuzz/test_fuzz_parse_emit.cpp
+++ b/test/test_fuzz/test_fuzz_parse_emit.cpp
@@ -3,7 +3,7 @@
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *str, size_t len)
 {
-    static std::atomic_uint32_t case_number{0};
+    static std::atomic<uint32_t> case_number{0};
     c4::csubstr src = {reinterpret_cast<const char*>(str), len};
     return c4::yml::fuzztest_parse_emit(case_number++, src);
 }