diff --git a/.github/workflows/dry-run.yml b/.github/workflows/dry-run.yml
index 9e3e8883a..b91ac98a6 100644
--- a/.github/workflows/dry-run.yml
+++ b/.github/workflows/dry-run.yml
@@ -88,16 +88,17 @@ jobs:
 
       - uses: msys2/setup-msys2@v2
         with:
-          msystem: UCRT64
+          msystem: CLANG64
           path-type: inherit
           install: >-
-            mingw-w64-ucrt-x86_64-gcc
-            mingw-w64-ucrt-x86_64-zlib
+            mingw-w64-clang-x86_64-clang
+            mingw-w64-clang-x86_64-compiler-rt
+            mingw-w64-clang-x86_64-zlib
             make
 
       - name: Test
         shell: msys2 {0}
-        run: scripts/test.sh
+        run: scripts/test.sh CC=clang CXX=clang++ WIN32_LIBS="-lws2_32 -lpsapi"
 
   # ── Step 3: Build binaries (standard + UI, all OS) ──────────
   build-unix:
@@ -166,11 +167,11 @@ jobs:
 
       - uses: msys2/setup-msys2@v2
         with:
-          msystem: UCRT64
+          msystem: CLANG64
           path-type: inherit
           install: >-
-            mingw-w64-ucrt-x86_64-gcc
-            mingw-w64-ucrt-x86_64-zlib
+            mingw-w64-clang-x86_64-clang
+            mingw-w64-clang-x86_64-zlib
             make
 
       - uses: actions/setup-node@v4
@@ -179,7 +180,7 @@ jobs:
 
       - name: Build standard binary
         shell: msys2 {0}
-        run: scripts/build.sh
+        run: scripts/build.sh CC=clang CXX=clang++ WIN32_LIBS="-lws2_32 -lpsapi"
 
       - name: Archive standard binary
         shell: pwsh
@@ -189,7 +190,7 @@ jobs:
 
       - name: Build UI binary
         shell: msys2 {0}
-        run: scripts/build.sh --with-ui
+        run: scripts/build.sh --with-ui CC=clang CXX=clang++ WIN32_LIBS="-lws2_32 -lpsapi"
 
       - name: Archive UI binary
         shell: pwsh
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 801a60864..01d1efd38 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -102,16 +102,17 @@ jobs:
 
       - uses: msys2/setup-msys2@v2
         with:
-          msystem: UCRT64
+          msystem: CLANG64
           path-type: inherit
           install: >-
-            mingw-w64-ucrt-x86_64-gcc
-            mingw-w64-ucrt-x86_64-zlib
+            mingw-w64-clang-x86_64-clang
+            mingw-w64-clang-x86_64-compiler-rt
+            mingw-w64-clang-x86_64-zlib
             make
 
       - name: Test
         shell: msys2 {0}
-        run: scripts/test.sh
+        run: scripts/test.sh CC=clang CXX=clang++ WIN32_LIBS="-lws2_32 -lpsapi"
 
   # ── Step 3: Build binaries (standard + UI, all OS) ──────────
   build-unix:
@@ -180,11 +181,11 @@ jobs:
 
       - uses: msys2/setup-msys2@v2
         with:
-          msystem: UCRT64
+          msystem: CLANG64
           path-type: inherit
           install: >-
-            mingw-w64-ucrt-x86_64-gcc
-            mingw-w64-ucrt-x86_64-zlib
+            mingw-w64-clang-x86_64-clang
+            mingw-w64-clang-x86_64-zlib
             make
 
       - uses: actions/setup-node@v4
@@ -193,7 +194,7 @@ jobs:
 
       - name: Build standard binary
         shell: msys2 {0}
-        run: scripts/build.sh --version ${{ inputs.version }}
+        run: scripts/build.sh --version ${{ inputs.version }} CC=clang CXX=clang++ WIN32_LIBS="-lws2_32 -lpsapi"
 
       - name: Archive standard binary
         shell: pwsh
@@ -203,7 +204,7 @@ jobs:
 
       - name: Build UI binary
         shell: msys2 {0}
-        run: scripts/build.sh --with-ui --version ${{ inputs.version }}
+        run: scripts/build.sh --with-ui --version ${{ inputs.version }} CC=clang CXX=clang++ WIN32_LIBS="-lws2_32 -lpsapi"
 
       - name: Archive UI binary
         shell: pwsh
diff --git a/Makefile.cbm b/Makefile.cbm
index fa7f25da4..39098f1d2 100644
--- a/Makefile.cbm
+++ b/Makefile.cbm
@@ -61,13 +61,10 @@ CXXFLAGS_COMMON = -std=c++14 -Wall -Wextra -Werror \
 CFLAGS_PROD = $(CFLAGS_COMMON) -O2 $(CFLAGS_EXTRA)
 CXXFLAGS_PROD = $(CXXFLAGS_COMMON) -O2
 
-# Test flags: debug + sanitizers
-CFLAGS_TEST = $(CFLAGS_COMMON) -g -O1 \
-              -fsanitize=address,undefined \
-              -fno-omit-frame-pointer
-CXXFLAGS_TEST = $(CXXFLAGS_COMMON) -g -O1 \
-                -fsanitize=address,undefined \
-                -fno-omit-frame-pointer
+# Test flags: debug + sanitizers (override SANITIZE= to disable on Windows)
+SANITIZE = -fsanitize=address,undefined -fno-omit-frame-pointer
+CFLAGS_TEST = $(CFLAGS_COMMON) -g -O1 $(SANITIZE)
+CXXFLAGS_TEST = $(CXXFLAGS_COMMON) -g -O1 $(SANITIZE)
 
 # TSan (can't combine with ASan)
 CFLAGS_TSAN = $(CFLAGS_COMMON) -g -O1 \
@@ -80,7 +77,7 @@ CXXFLAGS_TSAN = $(CXXFLAGS_COMMON) -g -O1 \
 WIN32_LIBS ?=
 
 LDFLAGS = -lm -lstdc++ -lpthread -lz $(LIBGIT2_LIBS) $(WIN32_LIBS)
-LDFLAGS_TEST = -lm -lstdc++ -lpthread -lz -fsanitize=address,undefined $(LIBGIT2_LIBS) $(WIN32_LIBS)
+LDFLAGS_TEST = -lm -lstdc++ -lpthread -lz $(SANITIZE) $(LIBGIT2_LIBS) $(WIN32_LIBS)
 LDFLAGS_TSAN = -lm -lstdc++ -lpthread -lz -fsanitize=thread $(LIBGIT2_LIBS) $(WIN32_LIBS)
 
 # ── Source files ─────────────────────────────────────────────────
@@ -195,7 +192,7 @@ UI_SRCS = \
 MONGOOSE_SRC = vendored/mongoose/mongoose.c
 MONGOOSE_CFLAGS = -std=c11 -D_DEFAULT_SOURCE -O2 -w -Ivendored -DMG_ENABLE_LOG=0
 MONGOOSE_CFLAGS_TEST = -std=c11 -D_DEFAULT_SOURCE -g -O1 -w -Ivendored -DMG_ENABLE_LOG=0 \
-                       -fsanitize=address,undefined -fno-omit-frame-pointer
+                       $(SANITIZE)
 
 # mimalloc (vendored, global allocator override)
 MIMALLOC_SRC = vendored/mimalloc/src/static.c
@@ -291,7 +288,7 @@ BUILD_DIR = build/c
 # Grammar + tree-sitter runtime: compiled without -Werror (upstream code has warnings)
 GRAMMAR_CFLAGS = -std=c11 -D_DEFAULT_SOURCE -O2 -w -I$(CBM_DIR) -I$(TS_INCLUDE) -I$(TS_SRC)
 GRAMMAR_CFLAGS_TEST = -std=c11 -D_DEFAULT_SOURCE -g -O1 -w -I$(CBM_DIR) -I$(TS_INCLUDE) -I$(TS_SRC) \
-                      -fsanitize=address,undefined -fno-omit-frame-pointer
+                      $(SANITIZE)
 GRAMMAR_CFLAGS_TSAN = -std=c11 -D_DEFAULT_SOURCE -g -O1 -w -I$(CBM_DIR) -I$(TS_INCLUDE) -I$(TS_SRC) \
                       -fsanitize=thread -fno-omit-frame-pointer
 
@@ -325,7 +322,7 @@ $(BUILD_DIR)/ts_runtime.o: $(CBM_DIR)/ts_runtime.c | $(BUILD_DIR)
 	$(CC) $(GRAMMAR_CFLAGS_TEST) -c -o $@ $<
 
 $(BUILD_DIR)/lsp_all.o: $(CBM_DIR)/lsp_all.c | $(BUILD_DIR)
-	$(CC) $(GRAMMAR_CFLAGS_TEST) -fsanitize=address,undefined -fno-omit-frame-pointer -c -o $@ $<
+	$(CC) $(GRAMMAR_CFLAGS_TEST) $(SANITIZE) -c -o $@ $<
 
 $(BUILD_DIR)/preprocessor.o: $(CBM_DIR)/preprocessor.cpp | $(BUILD_DIR)
 	$(CXX) $(CXXFLAGS_TEST) -w -I$(CBM_DIR)/vendored -c -o $@ $<
@@ -357,7 +354,7 @@ SQLITE3_OBJ_TEST = $(BUILD_DIR)/sqlite3.o
 SQLITE3_OBJ_PROD = $(BUILD_DIR)/prod_sqlite3.o
 
 $(BUILD_DIR)/sqlite3.o: $(SQLITE3_SRC) | $(BUILD_DIR)
-	$(CC) $(SQLITE3_CFLAGS_TEST) -fsanitize=address,undefined -fno-omit-frame-pointer -c -o $@ $<
+	$(CC) $(SQLITE3_CFLAGS_TEST) $(SANITIZE) -c -o $@ $<
 
 $(BUILD_DIR)/prod_sqlite3.o: $(SQLITE3_SRC) | $(BUILD_DIR)
 	$(CC) $(SQLITE3_CFLAGS) -c -o $@ $<
diff --git a/scripts/test.sh b/scripts/test.sh
index b35f7ea81..aa45811ea 100755
--- a/scripts/test.sh
+++ b/scripts/test.sh
@@ -38,10 +38,12 @@ done
 # shellcheck source=env.sh
 source "$ROOT/scripts/env.sh"
 
-# Forward CC/CXX from args
+# Forward CC/CXX and collect make-passthrough args (WIN32_LIBS=)
+MAKE_ARGS=""
 for arg in "$@"; do
     case "$arg" in
         CC=*|CXX=*) export "${arg}" ;;
+        WIN32_LIBS=*) MAKE_ARGS="$MAKE_ARGS $arg" ;;
         --arch|--arch=*) ;; # already handled
         arm64|x86_64) ;; # already handled
     esac
@@ -56,6 +58,6 @@ verify_compiler "$CC"
 scripts/clean.sh
 
 # Step 2 + 3: Build and run tests (with arch prefix on macOS)
-$ARCH_PREFIX make -j"$NPROC" -f Makefile.cbm test
+$ARCH_PREFIX make -j"$NPROC" -f Makefile.cbm test $MAKE_ARGS
 
 echo "=== All tests passed ==="