diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3acfe2c4..cfaea815 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -71,7 +71,7 @@ jobs:
       run: make $FLAGS
       env:
         FLAGS: ${{ format('{0} {1} {2}', steps.make_flags.outputs.proto_flags, steps.make_flags.outputs.compiler_flags, steps.make_flags.outputs.debug_flags) }}
-  build_windows:
+  build_windows_msvc:
     runs-on: windows-latest
     strategy:
       fail-fast: false
@@ -86,3 +86,25 @@ jobs:
       uses: actions/checkout@v4
     - name: Build and run tests
       run: nmake /F Makefile.windows
+  build_windows_msys2:
+    runs-on: windows-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        sys: [mingw64, mingw32, ucrt64, clang64]
+    steps:
+    - name: Set up MSYS2 and compiler
+      uses: msys2/setup-msys2@v2
+      with:
+        msystem: ${{matrix.sys}}
+        pacboy: >-
+          toolchain:p
+        install: >-
+          make
+          diff
+    - name: Check out code
+      uses: actions/checkout@v4
+    - name: Build and run tests
+      shell: msys2 {0}
+      run: |
+        make
diff --git a/Makefile b/Makefile
index 0de4c8d3..532d91fd 100644
--- a/Makefile
+++ b/Makefile
@@ -35,6 +35,10 @@ OBJ_FILES := $(SRC_FILES:.c=.o)
 
 override CFLAGS += -g -I. -I./vendor -I./src/include -I./src/postgres/include -Wall -Wno-unused-function -Wno-unused-value -Wno-unused-variable -fno-strict-aliasing -fwrapv -fPIC
 
+ifeq ($(OS),Windows_NT)
+override CFLAGS += -I./src/postgres/include/port/win32
+endif
+
 override PG_CONFIGURE_FLAGS += -q --without-readline --without-zlib --without-icu
 
 override TEST_CFLAGS += -g -I. -I./vendor -Wall