diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 0f04816ac..4dcab274e 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -303,6 +303,7 @@ msys2-mingw32:
   variables:
     MSYSTEM: "MINGW32"
     CHERE_INVOKING: "yes"
+    CFLAGS: -coverage -ftest-coverage -fprofile-arcs
   script:
     - C:\msys64\usr\bin\pacman --noconfirm -Syyuu --ask 20
     - C:\msys64\usr\bin\bash .gitlab-ci/show-execution-environment.sh
@@ -317,6 +318,28 @@ msys2-mingw32:
       - _build/meson-logs
       - _coverage/
 
+msys2-clang64:
+  extends: .only-schedules
+  stage: build
+  tags:
+    - win32-ps
+  needs: []
+  variables:
+    MSYSTEM: "CLANG64"
+    CHERE_INVOKING: "yes"
+  script:
+    - C:\msys64\usr\bin\pacman --noconfirm -Syyuu --ask 20
+    - C:\msys64\usr\bin\bash .gitlab-ci/show-execution-environment.sh
+    - C:\msys64\usr\bin\bash -lc "bash -x ./.gitlab-ci/test-msys2.sh"
+  artifacts:
+    reports:
+      junit: "_build/meson-logs/testlog.junit.xml"
+    name: "glib-${env:CI_JOB_NAME}-${env:CI_COMMIT_REF_NAME}"
+    when: always
+    expire_in: 1 week
+    paths:
+      - _build/meson-logs
+
 vs2017-x64:
   extends: .only-default
   stage: build
diff --git a/.gitlab-ci/test-msys2.sh b/.gitlab-ci/test-msys2.sh
index a345fda6a..85394a754 100755
--- a/.gitlab-ci/test-msys2.sh
+++ b/.gitlab-ci/test-msys2.sh
@@ -1,29 +1,24 @@
 #!/bin/bash
 
-set -e
+set -ex
 
 export PATH="/c/msys64/$MSYSTEM/bin:$PATH"
-if [[ "$MSYSTEM" == "MINGW32" ]]; then
-    export MSYS2_ARCH="i686"
-else
-    export MSYS2_ARCH="x86_64"
-fi
 
 pacman --noconfirm -Suy
 
 pacman --noconfirm -S --needed \
     base-devel \
     lcov \
-    mingw-w64-$MSYS2_ARCH-ccache \
-    mingw-w64-$MSYS2_ARCH-gettext \
-    mingw-w64-$MSYS2_ARCH-libffi \
-    mingw-w64-$MSYS2_ARCH-meson \
-    mingw-w64-$MSYS2_ARCH-pcre2 \
-    mingw-w64-$MSYS2_ARCH-python3 \
-    mingw-w64-$MSYS2_ARCH-python-pip \
-    mingw-w64-$MSYS2_ARCH-toolchain \
-    mingw-w64-$MSYS2_ARCH-zlib \
-    mingw-w64-$MSYS2_ARCH-libelf
+    "${MINGW_PACKAGE_PREFIX}"-ccache \
+    "${MINGW_PACKAGE_PREFIX}"-gettext \
+    "${MINGW_PACKAGE_PREFIX}"-libffi \
+    "${MINGW_PACKAGE_PREFIX}"-meson \
+    "${MINGW_PACKAGE_PREFIX}"-pcre2 \
+    "${MINGW_PACKAGE_PREFIX}"-python3 \
+    "${MINGW_PACKAGE_PREFIX}"-python-pip \
+    "${MINGW_PACKAGE_PREFIX}"-toolchain \
+    "${MINGW_PACKAGE_PREFIX}"-zlib \
+    "${MINGW_PACKAGE_PREFIX}"-libelf
 
 mkdir -p _coverage
 mkdir -p _ccache
@@ -34,28 +29,39 @@ export CCACHE_BASEDIR CCACHE_DIR
 pip3 install --upgrade --user meson==0.60.3
 
 PATH="$(cygpath "$USERPROFILE")/.local/bin:$HOME/.local/bin:$PATH"
-CFLAGS="-coverage -ftest-coverage -fprofile-arcs"
 DIR="$(pwd)"
 export PATH CFLAGS
 
-meson --werror --buildtype debug _build
+if [[ "$MSYSTEM" == "CLANG64" ]]; then
+    # FIXME: fix the clang build warnings
+    # shellcheck disable=SC2086
+    meson ${MESON_COMMON_OPTIONS} _build
+else
+    # shellcheck disable=SC2086
+    meson ${MESON_COMMON_OPTIONS} --werror _build
+fi
+
 cd _build
 ninja
 
-lcov \
-    --quiet \
-    --config-file "${DIR}"/.lcovrc \
-    --directory "${DIR}/_build" \
-    --capture \
-    --initial \
-    --output-file "${DIR}/_coverage/${CI_JOB_NAME}-baseline.lcov"
+if [[ "$CFLAGS" == *"-coverage"* ]]; then
+    lcov \
+        --quiet \
+        --config-file "${DIR}"/.lcovrc \
+        --directory "${DIR}/_build" \
+        --capture \
+        --initial \
+        --output-file "${DIR}/_coverage/${CI_JOB_NAME}-baseline.lcov"
+fi
 
 # FIXME: fix the test suite
 meson test --timeout-multiplier "${MESON_TEST_TIMEOUT_MULTIPLIER}" --no-suite flaky || true
 
-lcov \
-    --quiet \
-    --config-file "${DIR}"/.lcovrc \
-    --directory "${DIR}/_build" \
-    --capture \
-    --output-file "${DIR}/_coverage/${CI_JOB_NAME}.lcov"
+if [[ "$CFLAGS" == *"-coverage"* ]]; then
+    lcov \
+        --quiet \
+        --config-file "${DIR}"/.lcovrc \
+        --directory "${DIR}/_build" \
+        --capture \
+        --output-file "${DIR}/_coverage/${CI_JOB_NAME}.lcov"
+fi
diff --git a/gio/tests/win32-streams.c b/gio/tests/win32-streams.c
index 6451a9faa..9c32a56b2 100644
--- a/gio/tests/win32-streams.c
+++ b/gio/tests/win32-streams.c
@@ -40,7 +40,8 @@ static gpointer
 writer_thread (gpointer user_data)
 {
   GOutputStream *out;
-  gssize nwrote, offset;
+  gssize nwrote;
+  size_t offset;
   GError *err = NULL;
   HANDLE out_handle;
 
@@ -58,7 +59,7 @@ writer_thread (gpointer user_data)
       g_usleep (10);
 
       offset = 0;
-      while (offset < (gssize) sizeof (DATA))
+      while (offset < sizeof (DATA))
 	{
 	  nwrote = g_output_stream_write (out, DATA + offset,
 					  sizeof (DATA) - offset,
diff --git a/glib/gatomic.h b/glib/gatomic.h
index e1b5d2391..8c6a0877e 100644
--- a/glib/gatomic.h
+++ b/glib/gatomic.h
@@ -241,7 +241,8 @@ G_END_DECLS
  * https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1715#note_1024120. */
 #define g_atomic_pointer_compare_and_exchange(atomic, oldval, newval) \
   (G_GNUC_EXTENSION ({                                                       \
-    G_STATIC_ASSERT (sizeof (oldval) == sizeof (gpointer));                  \
+    G_STATIC_ASSERT (sizeof (static_cast<glib_typeof (*(atomic))>((oldval))) \
+                     == sizeof (gpointer));                                  \
     glib_typeof (*(atomic)) gapcae_oldval = (oldval);                        \
     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer));                 \
     (void) (0 ? (gpointer) *(atomic) : NULL);                                \
diff --git a/glib/gfileutils.c b/glib/gfileutils.c
index f0c8f6776..44c22f3ee 100644
--- a/glib/gfileutils.c
+++ b/glib/gfileutils.c
@@ -1143,7 +1143,7 @@ write_to_file (const gchar  *contents,
     {
       gssize s;
 
-      s = write (fd, contents, MIN (length, G_MAXSSIZE));
+      s = write (fd, contents, MIN (length, G_MAXSIZE));
 
       if (s < 0)
         {
diff --git a/glib/gnulib/meson.build b/glib/gnulib/meson.build
index bdd623385..c8040f648 100644
--- a/glib/gnulib/meson.build
+++ b/glib/gnulib/meson.build
@@ -3,6 +3,13 @@
 extra_gnulib_args = cc.get_supported_arguments([
   '-Wno-format-nonliteral', '-Wno-duplicated-branches'])
 
+if host_system == 'windows' and cc.get_id() == 'clang'
+  extra_gnulib_args += cc.get_supported_arguments([
+    '-Wno-unused-but-set-variable',
+    '-Wno-implicit-fallthrough',
+  ])
+endif
+
 math_h_config = configuration_data ()
 
 unneeded_funcs = [
diff --git a/glib/tests/cxx.cpp b/glib/tests/cxx.cpp
index 045457c6e..aa5e0cb57 100644
--- a/glib/tests/cxx.cpp
+++ b/glib/tests/cxx.cpp
@@ -186,7 +186,11 @@ test_steal_pointer (void)
 int
 main (int argc, char *argv[])
 {
+#if __cplusplus >= 201103L
   g_test_init (&argc, &argv, NULL);
+#else
+  g_test_init (&argc, &argv, static_cast<void *>(NULL));
+#endif
 
   g_test_add_func ("/C++/typeof", test_typeof);
   g_test_add_func ("/C++/atomic-pointer-compare-and-exchange", test_atomic_pointer_compare_and_exchange);
diff --git a/meson.build b/meson.build
index c49815a9c..1b2601791 100644
--- a/meson.build
+++ b/meson.build
@@ -467,6 +467,7 @@ if cc.get_id() == 'gcc' or cc.get_id() == 'clang'
     '-Werror=implicit-function-declaration',
     '-Werror=missing-prototypes',
     '-Werror=pointer-sign',
+    '-Wno-string-plus-int',
   ]
   warning_cxx_args = warning_common_args
   warning_objc_args = warning_c_args