diff --git a/.bcr/presubmit.yml b/.bcr/presubmit.yml
index 5d004e8..47fe577 100644
--- a/.bcr/presubmit.yml
+++ b/.bcr/presubmit.yml
@@ -3,8 +3,10 @@ matrix:
   - 7.x
   - 8.x
   platform:
-  - ubuntu2404
-  - macos
+    - debian11
+    - ubuntu2404
+    - macos
+    - windows
 tasks:
   verify_targets:
     name: Verify build targets
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 76ec374..2958c7c 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -21,7 +21,7 @@ jobs:
         os: [ubuntu-latest]
         bazel_mode: [bzlmod, workspace]
         compiler: [gcc]
-        gcc_version: [11, 12, 13]
+        gcc_version: [11, 12, 13, 14]
         bazel_config: [cpp23, opt]
         proto_version: ['30.0']
         exclude:
@@ -29,13 +29,40 @@ jobs:
             gcc_version: 11
           - bazel_mode: workspace
             gcc_version: 13
+          - bazel_mode: workspace
+            gcc_version: 14
           - bazel_config: cpp23
             gcc_version: 11
           - bazel_config: cpp23
             gcc_version: 12
+          - bazel_config: cpp23
+            gcc_version: 13
+
+    uses: ./.github/workflows/test.yml
+    with:
+      os: ${{ matrix.os }}
+      bazel_mode: ${{ matrix.bazel_mode }}
+      compiler: ${{ matrix.compiler }}
+      gcc_version: ${{ matrix.gcc_version }}
+      bazel_config: ${{ matrix.bazel_config }}
+      module_version: "proto${{ matrix.proto_version }}"
+      module_default: proto30.0
+
+  test-windows:
+    needs: pre-commit
+    secrets: inherit
+    strategy:
+      matrix:
+        os: [windows-latest]
+        bazel_mode: [bzlmod]
+        compiler: [mingw, native]
+        gcc_version: ['']
+        bazel_config: [opt]
+        proto_version: ['30.0']
 
     uses: ./.github/workflows/test.yml
     with:
+      continue-on-error: true
       os: ${{ matrix.os }}
       bazel_mode: ${{ matrix.bazel_mode }}
       compiler: ${{ matrix.compiler }}
@@ -155,7 +182,7 @@ jobs:
       module_default: proto30.0
 
   done:
-    needs: [pre-commit, test-gcc, test-clang, test-bcr]
+    needs: [pre-commit, test-bcr, test-clang, test-gcc, test-windows]
     runs-on: ubuntu-latest
     steps:
       - name: Done
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 70a2783..6a1a62a 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -65,12 +65,15 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: bazelbuild/setup-bazelisk@v3
+      - uses: egor-tensin/setup-mingw@v2
+        if: ${{inputs.compiler == 'mingw' && startsWith(inputs.os, 'windows')}}
+        with:
+          platform: ${{runner.arch}}
       - uses: egor-tensin/setup-gcc@v1
-        if: ${{inputs.compiler == 'gcc' && inputs.gcc_version != ''}}
+        if: ${{inputs.compiler == 'gcc' && inputs.gcc_version != '' && !startsWith(inputs.os, 'windows')}}
         with:
           version: ${{inputs.gcc_version}}
           platform: ${{runner.arch}}
-
       - uses: actions/cache/restore@v4
         id: cache_restore
         with:
@@ -81,7 +84,9 @@ jobs:
               ${{env.CACHE_KEY_PREFIX}}-refs/heads/main
               ${{env.CACHE_KEY_PREFIX}}
 
+
       - name: Build and Test
+        shell: bash
         run: |
           if [ "${{inputs.compiler}}:${{inputs.gcc_version}}" == "gcc:" ]; then
             echo "ERROR: When compiler=='gcc', then a valid 'compiler_version' must be given."
@@ -114,7 +119,7 @@ jobs:
           elif [ "${{inputs.compiler}}" == "gcc" ]; then
             export CC=/usr/local/bin/gcc
             export CXX=/usr/local/bin/g++
-          elif [ "${{inputs.compiler}}" == "native" ]; then
+          elif [ "${{inputs.compiler}}" == "mingw" ] || [ "${{inputs.compiler}}" == "native" ]; then
             # Use whatever is found!
             [ -n "${CC}" ] && [ -x "${CC}" ] && echo "CC: $(${CC} --version)"
             [ -n "${CXX}" ] && [ -x "${CXX}" ] && echo "CXX: $(${CXX} --version)"
@@ -149,7 +154,7 @@ jobs:
             key: ${{env.CACHE_KEY_PREFIX}}-${{github.ref}}-${{github.sha}}
 
       - name: Cleanup old caches
-        if: ${{!startsWith(github.ref, 'refs/tags/') && steps.cache_restore.outputs.cache-hit}}
+        if: ${{!startsWith(github.ref, 'refs/tags/') && steps.cache_restore.outputs.cache-hit && !startsWith(inputs.os, 'windows')}}
         run: |
           set -euo pipefail
           PREFIX="${{env.CACHE_KEY_PREFIX}}-${{github.ref}}"
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a4961f8..da28de5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 # 1.2.1
 
+* Added windows and new gcc versions to release checks.
+
 # 1.2.0
 
 * Added std::optional variants for file reading.
diff --git a/README.md b/README.md
index 738074a..6314acf 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,11 @@
 This package contains a collection of utilities around Google's [Protocolbuffer](https://github.com/protocolbuffers/protobuf). The functions offered in this packages are widely used across Google's C++ code base and have saved tens of thousands of engineering hours. Some of these functons were originally implemented by the author and later re-implemented or cloned (see below).
 
-The project works with Google's proto library version 27, 28, 29 and 30. Packages are available at [Bazel Central Registry](https://registry.bazel.build/modules/helly25_proto) and [Github](https://github.com/helly25/proto/releases).
+The project works with:
+* Google's proto library version 27, 28, 29, 30
+* Operating system: MacOS, Ubuntu, Windows
+* Compiler: GCC [11, 14], Clang [17.0.4, 20.1.0]
+
+Packages are available at [Bazel Central Registry](https://registry.bazel.build/modules/helly25_proto) and [Github](https://github.com/helly25/proto/releases).
 
 [![Test](https://github.com/helly25/proto/actions/workflows/main.yml/badge.svg)](https://github.com/helly25/proto/actions/workflows/main.yml)
 
diff --git a/bazelmod/llvm.20.1.0.MODULE.bazel b/bazelmod/llvm.20.1.0.MODULE.bazel
index cd3e540..3dfe70d 100644
--- a/bazelmod/llvm.20.1.0.MODULE.bazel
+++ b/bazelmod/llvm.20.1.0.MODULE.bazel
@@ -13,32 +13,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-bazel_dep(name = "toolchains_llvm", version = "1.3.0")
-git_override(
-    module_name = "toolchains_llvm",
-    commit = "e831f94a8b7f3a39391f5822adcab8e4d443c03b",  # Add more tools by default (#463)
-    remote = "https://github.com/bazel-contrib/toolchains_llvm",
-)
+bazel_dep(name = "toolchains_llvm", version = "1.4.0")
 
 llvm = use_extension("@toolchains_llvm//toolchain/extensions:llvm.bzl", "llvm", dev_dependency = True)
 llvm.toolchain(
     name = "llvm_toolchain_llvm",
     llvm_version = "20.1.0",
-    sha256 = {
-        "darwin-aarch64": "2c42ec26ec50c4bf8b95585f762b9d2f5b385d170dee772d9c1d6c9a7190dcef",
-        "linux-aarch64": "9d1bbf3f6d4d011e3b8b4b585f686bc968474917f37d3b82b4a534f456168c67",
-        "linux-x86_64": "954ac51498519f6ed9540714fb04bc401f70039b296a8160dd1559be380788d7",
-    },
-    strip_prefix = {
-        "darwin-aarch64": "LLVM-20.1.0-macOS-ARM64",
-        "linux-aarch64": "LLVM-20.1.0-Linux-ARM64",
-        "linux-x86_64": "LLVM-20.1.0-Linux-X64",
-    },
-    urls = {
-        "darwin-aarch64": ["https://github.com/llvm/llvm-project/releases/download/llvmorg-20.1.0/LLVM-20.1.0-macOS-ARM64.tar.xz"],
-        "linux-aarch64": ["https://github.com/llvm/llvm-project/releases/download/llvmorg-20.1.0/LLVM-20.1.0-Linux-ARM64.tar.xz"],
-        "linux-x86_64": ["https://github.com/llvm/llvm-project/releases/download/llvmorg-20.1.0/LLVM-20.1.0-Linux-X64.tar.xz"],
-    },
 )
 use_repo(llvm, "llvm_toolchain_llvm")
 
diff --git a/bazelmod/llvm.MODULE.bazel b/bazelmod/llvm.MODULE.bazel
index d68674a..dab3ba3 100644
--- a/bazelmod/llvm.MODULE.bazel
+++ b/bazelmod/llvm.MODULE.bazel
@@ -13,12 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-bazel_dep(name = "toolchains_llvm", version = "1.3.0")
-git_override(
-    module_name = "toolchains_llvm",
-    commit = "e831f94a8b7f3a39391f5822adcab8e4d443c03b",  # Add more tools by default (#463)
-    remote = "https://github.com/bazel-contrib/toolchains_llvm",
-)
+bazel_dep(name = "toolchains_llvm", version = "1.4.0")
 
 llvm = use_extension("@toolchains_llvm//toolchain/extensions:llvm.bzl", "llvm", dev_dependency = True)
 llvm.toolchain(