diff --git a/.github/workflows/buildwheel.yml b/.github/workflows/buildwheel.yml
index f8b4dd13..18fa1d8e 100644
--- a/.github/workflows/buildwheel.yml
+++ b/.github/workflows/buildwheel.yml
@@ -21,14 +21,19 @@ jobs:
 
       - uses: msys2/setup-msys2@v2
         with:
-          msystem: mingw64
+          msystem: ucrt64
           # path-type inherit is used so that when cibuildwheel calls msys2 to
           # run bin/cibw_before_build_windows.sh the virtual environment
           # created by cibuildwheel will be available within msys2. The
           # msys2/setup-msys2 README warns that using inherit here can be
           # problematic in some situations. Maybe there is a better way to do
           # this.
-          path-type: inherit
+          #path-type: inherit
+          install: >-
+            m4
+            make
+            mingw-w64-ucrt-x86_64-gcc
+            mingw-w64-ucrt-x86_64-tools-git
         if: ${{ matrix.os == 'windows-2019' }}
 
       - name: Build wheels
@@ -42,13 +47,14 @@ jobs:
           CIBW_BEFORE_ALL_LINUX: bin/cibw_before_all_linux.sh
           CIBW_BEFORE_ALL_MACOS: bin/cibw_before_all_macosx.sh
           CIBW_BEFORE_ALL_WINDOWS: msys2 -c bin/cibw_before_all_windows.sh
-          CIBW_BEFORE_BUILD_WINDOWS: msys2 -c bin/cibw_before_build_windows.sh
+          CIBW_BEFORE_BUILD_WINDOWS: bin\cibw_before_build_windows.bat
           CIBW_BEFORE_BUILD: pip install numpy cython delvewheel
           CIBW_ENVIRONMENT: >
             C_INCLUDE_PATH=$(pwd)/.local/include/
             LIBRARY_PATH=$(pwd)/.local/lib/
             LD_LIBRARY_PATH=$(pwd)/.local/lib:$LD_LIBRARY_PATH
             PYTHON_FLINT_MINGW64=true
+            MSYSTEM=UCRT64
           CIBW_REPAIR_WHEEL_COMMAND_WINDOWS: >-
             bin\cibw_repair_wheel_command_windows.bat {dest_dir} {wheel}
           CIBW_TEST_COMMAND: python -c "import flint; print(str(flint.fmpz(2)))"
diff --git a/bin/cibw.bat b/bin/cibw.bat
index a21ebb6d..28dc63dd 100644
--- a/bin/cibw.bat
+++ b/bin/cibw.bat
@@ -23,9 +23,11 @@ del /q wheelhouse\*
 
 set CIBW_BUILD=cp39-* cp310-* cp311-*
 set CIBW_SKIP=*-win32 *-manylinux_i686 *-musllinux_*
-set CIBW_BEFORE_ALL_WINDOWS=C:\msys64\usr\bin\bash bin/cibw_before_all_windows.sh
-set CIBW_BEFORE_BUILD_WINDOWS=C:\msys64\usr\bin\bash bin/cibw_before_build_windows.sh
-set CIBW_ENVIRONMENT=PYTHON_FLINT_MINGW64=true
+set CIBW_BEFORE_ALL_WINDOWS=msys2 -c bin/cibw_before_all_windows.sh
+set CIBW_BEFORE_BUILD_WINDOWS=bin\cibw_before_build_windows.bat
+set CIBW_ENVIRONMENT=^
+        PYTHON_FLINT_MINGW64=true ^
+        MSYSTEM=UCRT64
 set CIBW_REPAIR_WHEEL_COMMAND_WINDOWS=bin\cibw_repair_wheel_command_windows.bat {dest_dir} {wheel}
 set CIBW_TEST_COMMAND=python -c "import flint; print(str(flint.fmpz(2)))"
 
diff --git a/bin/cibw_before_all_windows.sh b/bin/cibw_before_all_windows.sh
index ea2f8a89..df96936b 100755
--- a/bin/cibw_before_all_windows.sh
+++ b/bin/cibw_before_all_windows.sh
@@ -13,8 +13,16 @@ echo '[build]' > setup.cfg
 echo 'compiler = mingw32' >> setup.cfg
 cat setup.cfg
 
+echo "NEED UCRT64 gcc:"
+which gcc
+
+echo $PATH
+
 # Install the mingw-w64 toolchain
-pacman -S --noconfirm mingw-w64-x86_64-gcc m4 make mingw-w64-x86_64-tools-git
+# pacman -S --noconfirm mingw-w64-x86_64-gcc m4 make mingw-w64-x86_64-tools-git
+
+# Install the mingw-ucrt toolchain
+# pacman -S --noconfirm mingw-w64-ucrt-x86_64-gcc m4 make mingw-w64-ucrt-x86_64-tools-git
 
 # This takes ~30mins
 bin/build_dependencies_unix.sh
diff --git a/bin/cibw_before_build_windows.bat b/bin/cibw_before_build_windows.bat
new file mode 100644
index 00000000..ff45fb4d
--- /dev/null
+++ b/bin/cibw_before_build_windows.bat
@@ -0,0 +1,6 @@
+SET
+FOR /F "tokens=* USEBACKQ" %%F IN (`python -c "import sys, os; print(os.path.dirname(sys.executable))"`) DO (
+	SET VIRTUAL_ENV_BIN=%%F
+)
+echo %VIRTUAL_ENV_BIN%
+msys2 -c bin/cibw_before_build_windows.sh
diff --git a/bin/cibw_before_build_windows.sh b/bin/cibw_before_build_windows.sh
index d0410b35..a3966127 100644
--- a/bin/cibw_before_build_windows.sh
+++ b/bin/cibw_before_build_windows.sh
@@ -5,6 +5,10 @@ set -o errexit
 # Uncomment this to run cibuildwheel locally on Windows:
 # export PATH=$PATH:/c/msys64/usr/bin:/c/msys64/mingw64/bin
 
+# msys2 will not inherit the PATH for the virtual environment
+export PATH=$PATH:$(cygpath ${VIRTUAL_ENV_BIN})
+echo PATH=$PATH
+
 # VER should be set be e.g. 310 for Python 3.10
 VER=`python -c 'import sys; print("%s%s" % sys.version_info[:2])'`
 echo VER=${VER}
@@ -14,7 +18,8 @@ echo VER=${VER}
 ###################################################
 
 which python
-PYTHONBIN=`dirname $(which python)`
+PYTHONBIN=$VIRTUAL_ENV_BIN
+echo PYTHONBIN=$PYTHONBIN
 PYTHONDIR=`dirname $PYTHONBIN`
 cfgfile=$PYTHONDIR/pyvenv.cfg
 homeline=`grep home $cfgfile`
@@ -40,4 +45,4 @@ mv libpython${VER}.a libs
 #  Install build dependencies                     #
 ###################################################
 
-pip install Cython numpy delvewheel
+pip install Cython numpy delvewheel wheel
diff --git a/bin/cibw_repair_wheel_command_windows.bat b/bin/cibw_repair_wheel_command_windows.bat
index 00e7d151..b136f171 100644
--- a/bin/cibw_repair_wheel_command_windows.bat
+++ b/bin/cibw_repair_wheel_command_windows.bat
@@ -9,5 +9,10 @@ set tempfile=tmpfile.deleteme
 set WHEELHOUSE=%1
 set WHEELNAME=%2
 
+FOR /F "tokens=* USEBACKQ" %%F IN (`python -c "import sys, os; print(os.path.dirname(sys.executable))"`) DO (
+	SET VIRTUAL_ENV_BIN=%%F
+)
+echo %VIRTUAL_ENV_BIN%
+
 msys2 -c bin/cibw_repair_wheel_command_windows.sh
 rem C:\msys64\usr\bin\bash bin/cibw_repair_wheel_command_windows.sh
diff --git a/bin/cibw_repair_wheel_command_windows.sh b/bin/cibw_repair_wheel_command_windows.sh
index c4827867..bb02d73f 100755
--- a/bin/cibw_repair_wheel_command_windows.sh
+++ b/bin/cibw_repair_wheel_command_windows.sh
@@ -9,6 +9,18 @@ set -o errexit
 # Uncomment this to run cibuildwheel locally on Windows:
 # export PATH=$PATH:/c/msys64/usr/bin:/c/msys64/mingw64/bin
 
+# msys2 will not inherit the PATH for the virtual environment in CI
+export PATH=$PATH:$(cygpath ${VIRTUAL_ENV_BIN})
+echo PATH=$PATH
+
+echo of VIRTUAL_ENV_BIN=$VIRTUAL_ENV_BIN
+echo Contents of VIRTUAL_ENV_BIN:
+ls $VIRTUAL_ENV_BIN
+
+which pip
+which wheel
+pip list
+
 # We cannot use ordinary command line arguments in CI because msys2 -c mangles
 # them. Instead we have a batch file to receive the arguments and convert them
 # into environment variables before calling this script. When running locally
@@ -46,5 +58,6 @@ popd
 # --no-mangle if strip has not been applied to all mingw64-created .dll and
 # .pyd files that are needed for the wheel.
 delvewheel repair $WHEELNAME 	\
-	-w $WHEELHOUSE		\
-	--add-path .local/bin:.local/lib/
+    -vv               \
+    -w $WHEELHOUSE    \
+    --add-path .local/bin:.local/lib/:/c/msys64/ucrt64/bin