diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index c3aad07..cbc734c 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -55,6 +55,133 @@ jobs:
         if: matrix.llvm == 19
         run:
           go test -v
+  test-windows:
+    runs-on: windows-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - llvm: 14
+            version: '14.0.6'
+            sha256: a46a843b0899d284f2a1c76e15aa9a6f3e939925ed008fd4b3b68c5f2f0c8231
+          - llvm: 15
+            version: '15.0.7'
+            sha256: 8c55ba91a041507bd927c5f82348c36ef3696485afb71c51bbcc35a014d179de
+          - llvm: 16
+            version: '16.0.6'
+            sha256: 8082a28d7ff50e5dfdace530935e3e59c37d11f1f8b52f43b7dc3b2fa130be66
+          - llvm: 17
+            version: '17.0.6'
+            sha256: 773f122cd79a54ecf3cbf1b1aff47543e95b12b4f91278b29c70cade37e3018c
+          - llvm: 18
+            version: '18.1.8'
+            sha256: 7cb37bafd78874e707d0c323f8e16e81503bc76867638ef1c634ee0451fac0be
+          - llvm: 19
+            version: '19.1.7'
+            sha256: d39689f23e1143a710a9120741ac3a1621fc4e2a81a143959bc870c60f9b85d1
+          - llvm: 20
+            version: '20.1.8'
+            sha256: 0944367aff9c3619f98dd0db78a1489018af9a8501b2533d17cc143a9624d853
+          - llvm: 21
+            version: '21.1.4'
+            sha256: f18f364b3aea5e4d09a4ed58d1c34b7220883912662e39935af96fabd603a912
+          - llvm: 22
+            version: '22.1.0'
+            sha256: 00199342f0cedfae60421d5d4ce0f1e217a06d7617611c8541372c47269c7084
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: '1.22'
+      - name: Set up MSYS2
+        uses: msys2/setup-msys2@v2
+        with:
+          msystem: MINGW64
+          path-type: inherit
+          update: true
+          install: >-
+            mingw-w64-x86_64-gcc
+            mingw-w64-x86_64-pkgconf
+      - name: Install LLVM ${{ matrix.llvm }}
+        shell: pwsh
+        run: |
+          $archiveName = 'llvm-${{ matrix.version }}-windows-gnu.zip'
+          $archive = Join-Path $env:RUNNER_TEMP $archiveName
+          $url = "https://github.com/yasuo-ozu/llvm-full/releases/download/v${{ matrix.version }}/$archiveName"
+          curl.exe --fail --location --retry 3 --output $archive $url
+          if ($LASTEXITCODE -ne 0) {
+            throw "failed to download $url"
+          }
+
+          $actualSha256 = (Get-FileHash -Algorithm SHA256 $archive).Hash.ToLowerInvariant()
+          if ($actualSha256 -ne '${{ matrix.sha256 }}') {
+            throw "expected SHA-256 ${{ matrix.sha256 }}, got $actualSha256"
+          }
+
+          $prefix = Join-Path $env:RUNNER_TEMP 'llvm-${{ matrix.version }}'
+          New-Item -ItemType Directory -Force -Path $prefix | Out-Null
+          7z x $archive "-o$prefix" -y
+          if ($LASTEXITCODE -ne 0) {
+            throw "failed to extract $archive"
+          }
+          Remove-Item $archive
+
+          if (-not (Test-Path (Join-Path $prefix 'bin\llvm-config.exe'))) {
+            throw "llvm-config.exe is missing from $prefix"
+          }
+          "LLVM_PREFIX=$prefix" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
+      - name: Test LLVM ${{ matrix.llvm }}
+        shell: msys2 {0}
+        run: |
+          set -euo pipefail
+
+          llvm_bin="$(cygpath -u "$LLVM_PREFIX")/bin"
+          export PATH="$llvm_bin:$PATH"
+          llvm_version="$(llvm-config --version)"
+          if [[ "$llvm_version" != '${{ matrix.version }}' ]]; then
+            echo "expected LLVM ${{ matrix.version }}, got $llvm_version" >&2
+            exit 1
+          fi
+
+          # Supply the installed LLVM's include and library paths through the
+          # versioned pkg-config name consumed by the Windows binding.
+          pc_dir="$(cygpath -u "$RUNNER_TEMP")/llvm-pkgconfig"
+          mkdir -p "$pc_dir"
+          cflags="$(llvm-config --cflags | tr '\r\n' '  ')"
+          # The release archives can embed their build machine's zstd import
+          # library path, and their static LLVM libraries require winpthread.
+          ldflags="$(llvm-config --ldflags --libs all --system-libs | tr '\r\n' '  ' | sed -E 's#[^[:space:]]*/mingw64/lib/libzstd\.dll\.a#-lzstd#g') -lwinpthread"
+          printf '%s\n' \
+            'Name: LLVM ${{ matrix.llvm }}' \
+            'Description: LLVM ${{ matrix.llvm }} host compiler and linker flags' \
+            "Version: $llvm_version" \
+            "Cflags: $cflags" \
+            "Libs: $ldflags" \
+            > "$pc_dir/llvm-${{ matrix.llvm }}.pc"
+
+          export CC=gcc
+          export CXX=g++
+          export CGO_ENABLED=1
+          PKG_CONFIG_PATH="$(cygpath -m "$pc_dir")"
+          export PKG_CONFIG_PATH
+          gcc --version
+          go test -v -tags=llvm${{ matrix.llvm }}
+      - name: Test default LLVM
+        if: matrix.llvm == 19
+        shell: msys2 {0}
+        run: |
+          set -euo pipefail
+          llvm_bin="$(cygpath -u "$LLVM_PREFIX")/bin"
+          export PATH="$llvm_bin:$PATH"
+          export CC=gcc
+          export CXX=g++
+          export CGO_ENABLED=1
+          pc_dir="$(cygpath -u "$RUNNER_TEMP")/llvm-pkgconfig"
+          PKG_CONFIG_PATH="$(cygpath -m "$pc_dir")"
+          export PKG_CONFIG_PATH
+          go test -v
   test-linux-fedora:
     # Fedora uses different paths than other systems, so testing it separately.
     runs-on: ubuntu-24.04
diff --git a/README.markdown b/README.markdown
index e66c391..3884324 100644
--- a/README.markdown
+++ b/README.markdown
@@ -11,8 +11,9 @@ This library provides bindings to a system-installed LLVM.
 
 Currently supported:
 
-  * LLVM 20, 19, 18, 17, 16, 15 and 14 from [apt.llvm.org](http://apt.llvm.org/) on Debian/Ubuntu.
-  * LLVM 20, 19, 18, 17, 16, 15 and 14 from Homebrew on macOS.
+  * LLVM 22, 21, 20, 19, 18, 17, 16, 15 and 14 from [apt.llvm.org](http://apt.llvm.org/) on Debian/Ubuntu.
+  * LLVM 22, 21, 20, 19, 18, 17, 16, 15 and 14 from Homebrew on macOS.
+  * LLVM 22, 21, 20, 19, 18, 17, 16, 15 and 14 in an MSYS2 MINGW64 environment on Windows (see the setup below).
   * Any of the above versions with a manually built LLVM through the `byollvm` build tag. You need to set up `CFLAGS`/`LDFLAGS` etc yourself in this case.
 
 You can select the LLVM version using a build tag, for example `-tags=llvm17`
@@ -26,6 +27,38 @@ If you have a supported LLVM installation, you should be able to do a simple `go
 
 You can use build tags to select a LLVM version. For example, use `-tags=llvm15` to select LLVM 15. Setting a build tag for a LLVM version that is not supported will be ignored.
 
+### Windows (MSYS2 MINGW64)
+
+The Windows bindings expect `pkg-config` metadata named after the selected LLVM
+major version, such as `llvm-19`. After installing a MinGW-compatible LLVM,
+`mingw-w64-x86_64-gcc`, and `mingw-w64-x86_64-pkgconf` in a MINGW64
+environment, generate that file from `llvm-config`:
+
+    pc_dir="$PWD/.llvm-pkgconfig"
+    mkdir -p "$pc_dir"
+    llvm_version="$(llvm-config --version)"
+    llvm_major="${llvm_version%%.*}"
+    case "$llvm_major" in
+      14|15|16|17|18|19|20|21|22) ;;
+      *) echo "unsupported LLVM version: $llvm_version" >&2; exit 1 ;;
+    esac
+    cflags="$(llvm-config --cflags | tr '\r\n' '  ')"
+    # Normalize the release build machine's zstd path and link winpthread.
+    ldflags="$(llvm-config --ldflags --libs all --system-libs | tr '\r\n' '  ' | sed -E 's#[^[:space:]]*/mingw64/lib/libzstd\.dll\.a#-lzstd#g') -lwinpthread"
+    printf '%s\n' \
+      "Name: LLVM $llvm_major" \
+      "Description: LLVM $llvm_major host compiler and linker flags" \
+      "Version: $llvm_version" \
+      "Cflags: $cflags" \
+      "Libs: $ldflags" \
+      > "$pc_dir/llvm-$llvm_major.pc"
+    export PKG_CONFIG_PATH="$(cygpath -m "$pc_dir")"
+    export CC=gcc CXX=g++ CGO_ENABLED=1
+    go test -tags="llvm$llvm_major"
+
+The Windows CI job in [`.github/workflows/go.yml`](.github/workflows/go.yml)
+shows the exact LLVM versions and SHA-256 checksums used by this project.
+
 ## License
 
 These LLVM bindings for Go originally come from LLVM, but they have since been [removed](https://discourse.llvm.org/t/rfc-remove-the-go-bindings/65725). Still, they remain under the same license as they were originally, which is the [Apache License 2.0 (with LLVM exceptions)](http://releases.llvm.org/9.0.0/LICENSE.TXT). Check upstream LLVM for detailed copyright information.
diff --git a/archive_test.go b/archive_test.go
index df8e876..db1d476 100644
--- a/archive_test.go
+++ b/archive_test.go
@@ -10,6 +10,7 @@ package llvm
 
 import (
 	"bytes"
+	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
@@ -74,7 +75,7 @@ func TestWriteArchiveRejectsInvalidMembers(t *testing.T) {
 		{name: "empty path", members: []ArchiveMember{{}}, want: "archive path is empty"},
 		{name: "no members", path: path, want: "archive has no members"},
 		{name: "empty member", path: path, members: []ArchiveMember{{}}, want: "has no file or memory buffer"},
-		{name: "missing file", path: path, members: []ArchiveMember{NewArchiveMemberFromFile(missing)}, want: missing},
+		{name: "missing file", path: path, members: []ArchiveMember{NewArchiveMemberFromFile(missing)}, want: fmt.Sprintf("%q", missing)},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
diff --git a/llvm_config_llvm14.go b/llvm_config_llvm14.go
index 9d38a5b..0178894 100644
--- a/llvm_config_llvm14.go
+++ b/llvm_config_llvm14.go
@@ -11,6 +11,8 @@ package llvm
 // #cgo linux        CPPFLAGS: -I/usr/lib/llvm-14/include -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
 // #cgo linux        CXXFLAGS: -std=c++14
 // #cgo linux        LDFLAGS: -L/usr/lib/llvm-14/lib  -lLLVM-14
+// #cgo windows      pkg-config: llvm-14
+// #cgo windows      CXXFLAGS: -std=c++14
 import "C"
 
 type run_build_sh int
diff --git a/llvm_config_llvm15.go b/llvm_config_llvm15.go
index 34aebc0..a049045 100644
--- a/llvm_config_llvm15.go
+++ b/llvm_config_llvm15.go
@@ -11,6 +11,8 @@ package llvm
 // #cgo linux        CPPFLAGS: -I/usr/lib/llvm-15/include -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
 // #cgo linux        CXXFLAGS: -std=c++14
 // #cgo linux        LDFLAGS: -L/usr/lib/llvm-15/lib  -lLLVM-15
+// #cgo windows      pkg-config: llvm-15
+// #cgo windows      CXXFLAGS: -std=c++14
 import "C"
 
 type run_build_sh int
diff --git a/llvm_config_llvm16.go b/llvm_config_llvm16.go
index 936ca0f..35cc410 100644
--- a/llvm_config_llvm16.go
+++ b/llvm_config_llvm16.go
@@ -11,6 +11,8 @@ package llvm
 // #cgo linux        CPPFLAGS: -I/usr/lib/llvm-16/include -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
 // #cgo linux        CXXFLAGS: -std=c++17
 // #cgo linux        LDFLAGS: -L/usr/lib/llvm-16/lib  -lLLVM-16
+// #cgo windows      pkg-config: llvm-16
+// #cgo windows      CXXFLAGS: -std=c++17
 import "C"
 
 type run_build_sh int
diff --git a/llvm_config_llvm17.go b/llvm_config_llvm17.go
index 6a00b39..815b687 100644
--- a/llvm_config_llvm17.go
+++ b/llvm_config_llvm17.go
@@ -11,6 +11,8 @@ package llvm
 // #cgo linux        CPPFLAGS: -I/usr/include/llvm-17 -I/usr/include/llvm-c-17 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
 // #cgo linux        CXXFLAGS: -std=c++17
 // #cgo linux        LDFLAGS: -L/usr/lib/llvm-17/lib  -lLLVM-17
+// #cgo windows      pkg-config: llvm-17
+// #cgo windows      CXXFLAGS: -std=c++17
 import "C"
 
 type run_build_sh int
diff --git a/llvm_config_llvm18.go b/llvm_config_llvm18.go
index c41fea0..27dd760 100644
--- a/llvm_config_llvm18.go
+++ b/llvm_config_llvm18.go
@@ -11,6 +11,8 @@ package llvm
 // #cgo linux        CPPFLAGS: -I/usr/include/llvm-18 -I/usr/include/llvm-c-18 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
 // #cgo linux        CXXFLAGS: -std=c++17
 // #cgo linux        LDFLAGS: -L/usr/lib/llvm-18/lib  -lLLVM-18
+// #cgo windows      pkg-config: llvm-18
+// #cgo windows      CXXFLAGS: -std=c++17
 import "C"
 
 type run_build_sh int
diff --git a/llvm_config_llvm19.go b/llvm_config_llvm19.go
index fea3f0b..83a0f1a 100644
--- a/llvm_config_llvm19.go
+++ b/llvm_config_llvm19.go
@@ -15,6 +15,8 @@ package llvm
 // #cgo linux        CPPFLAGS: -I/usr/include/llvm-19 -I/usr/include/llvm-c-19 -I/usr/lib64/llvm19/include -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
 // #cgo linux        CXXFLAGS: -std=c++17
 // #cgo linux        LDFLAGS: -L/usr/lib/llvm-19/lib -L/usr/lib64/llvm19/lib -lLLVM-19
+// #cgo windows      pkg-config: llvm-19
+// #cgo windows      CXXFLAGS: -std=c++17
 import "C"
 
 type run_build_sh int
diff --git a/llvm_config_llvm20.go b/llvm_config_llvm20.go
index d67281a..add4a07 100644
--- a/llvm_config_llvm20.go
+++ b/llvm_config_llvm20.go
@@ -15,6 +15,8 @@ package llvm
 // #cgo linux        CPPFLAGS: -I/usr/include/llvm-20 -I/usr/include/llvm-c-20 -I/usr/lib64/llvm20/include -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
 // #cgo linux        CXXFLAGS: -std=c++17
 // #cgo linux        LDFLAGS: -L/usr/lib/llvm-20/lib -L/usr/lib64/llvm20/lib64 -lLLVM-20
+// #cgo windows      pkg-config: llvm-20
+// #cgo windows      CXXFLAGS: -std=c++17
 import "C"
 
 type run_build_sh int
diff --git a/llvm_config_llvm21.go b/llvm_config_llvm21.go
index 263c2fc..bff0dba 100644
--- a/llvm_config_llvm21.go
+++ b/llvm_config_llvm21.go
@@ -14,6 +14,8 @@ package llvm
 // #cgo linux        CPPFLAGS: -I/usr/include/llvm-21 -I/usr/include/llvm-c-21 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
 // #cgo linux        CXXFLAGS: -std=c++17
 // #cgo linux        LDFLAGS: -L/usr/lib/llvm-21/lib -lLLVM-21
+// #cgo windows      pkg-config: llvm-21
+// #cgo windows      CXXFLAGS: -std=c++17
 import "C"
 
 type run_build_sh int
diff --git a/llvm_config_llvm22.go b/llvm_config_llvm22.go
index 103e930..3ae122f 100644
--- a/llvm_config_llvm22.go
+++ b/llvm_config_llvm22.go
@@ -14,6 +14,8 @@ package llvm
 // #cgo linux        CPPFLAGS: -I/usr/include/llvm-22 -I/usr/include/llvm-c-22 -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
 // #cgo linux        CXXFLAGS: -std=c++17
 // #cgo linux        LDFLAGS: -L/usr/lib/llvm-22/lib -lLLVM-22
+// #cgo windows      pkg-config: llvm-22
+// #cgo windows      CXXFLAGS: -std=c++17
 import "C"
 
 type run_build_sh int
diff --git a/llvm_config_windows_llvm20.go b/llvm_config_windows_llvm20.go
deleted file mode 100644
index 15d578a..0000000
--- a/llvm_config_windows_llvm20.go
+++ /dev/null
@@ -1,10 +0,0 @@
-//go:build !byollvm && windows && llvm20
-
-package llvm
-
-// #cgo CPPFLAGS: -I/usr/include/llvm -I/usr/include/llvm-c -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS
-// #cgo CXXFLAGS: -std=c++17
-// #cgo LDFLAGS: -Lllvm-20 -lLLVM-20.dll
-import "C"
-
-type run_build_sh int