diff --git a/.github/workflows/test-windows.yml b/.github/workflows/test-windows.yml
index 4a2b79cfd23..07f6ca443e3 100644
--- a/.github/workflows/test-windows.yml
+++ b/.github/workflows/test-windows.yml
@@ -7,26 +7,56 @@ jobs:
   
     runs-on: windows-2016
     strategy:
+      fail-fast: false
       matrix:
-        python-version:
-          - "3.5.4"
-          - "3.6.8"
-          - "3.7.4"
-        platform:
-          - name: "x86"
-            vars: "x86"
-            msbuild: "Win32"
-          - name: "x64"
-            vars: "x86_amd64"
-            msbuild: "x64"
+        python-version: ["3.5", "3.6", "3.7", "pypy3.6"]
+        architecture: ["x86", "x64"]
+        include:
+          - architecture: "x86"
+            platform-vcvars: "x86"
+            platform-msbuild: "Win32"
+          - architecture: "x64"
+            platform-vcvars: "x86_amd64"
+            platform-msbuild: "x64"
+          - python-version: "pypy3.6"
+            pypy-version: "pypy-c-jit-97588-7392d01b93d0-win32"
+            pypy-url: "http://buildbot.pypy.org/nightly/py3.6/pypy-c-jit-97588-7392d01b93d0-win32.zip"
+            # pypy-url: "https://bitbucket.org/pypy/pypy/downloads/${{ matrix.pypy-version }}.zip"
+        exclude:
+          - python-version: "pypy3.6"
+            architecture: "x64"
     
-    name: Python ${{ matrix.python-version }} ${{ matrix.platform.name }}
+    name: Python ${{ matrix.python-version }} ${{ matrix.architecture }}
     
     steps:
     - uses: actions/checkout@v1
+
+    - name: Install PyPy
+      if: "contains(matrix.python-version, 'pypy')"
+      run: |
+        curl -fsSL -o pypy3.zip "${{ matrix.pypy-url }}"
+        7z x pypy3.zip "-o$env:RUNNER_WORKSPACE\"
+        mv "$env:RUNNER_WORKSPACE\${{ matrix.pypy-version }}" "$env:RUNNER_WORKSPACE\${{ matrix.python-version }}"
+        $env:PYTHON="$env:RUNNER_WORKSPACE\${{ matrix.python-version }}"
+        # set env: pythonLocation
+        Write-Host "`#`#[set-env name=pythonLocation;]$env:PYTHON" # old syntax https://github.com/actions/toolkit/issues/61
+        Write-Host "::set-env name=pythonLocation::$env:PYTHON" # new syntax https://github.com/actions/toolkit/blob/5bb77ec03fea98332e41f9347c8fbb1ce1e48f4a/docs/commands.md
+        New-Item -ItemType SymbolicLink -Path "$env:PYTHON\python.exe" -Target "$env:PYTHON\pypy3.exe"
+        curl -fsSL -o get-pip.py https://bootstrap.pypa.io/get-pip.py
+        & $env:PYTHON\python.exe get-pip.py
+      shell: pwsh
+
+    # sets env: pythonLocation
+    - name: Set up Python
+      if: "!contains(matrix.python-version, 'pypy')"
+      uses: actions/setup-python@v1
+      with:
+        python-version: ${{ matrix.python-version }}
+        architecture: ${{ matrix.architecture }}
     
     - name: Fetch dependencies
       run: |
+        $env:PYTHON=$env:pythonLocation
         curl -fsSL -o pillow-depends.zip https://github.com/python-pillow/pillow-depends/archive/master.zip
         7z x pillow-depends.zip -oc:\
         mv c:\pillow-depends-master c:\pillow-depends
@@ -37,7 +67,6 @@ jobs:
         python.exe $env:GITHUB_WORKSPACE\winbuild\build_dep.py
         # .\build_deps.cmd
       env:
-        PYTHON: C:\hostedtoolcache\windows\Python\${{ matrix.python-version }}\${{ matrix.platform.name }}
         EXECUTABLE: bin\python.exe
       shell: pwsh
 
@@ -47,7 +76,7 @@ jobs:
         set INCLIB=%GITHUB_WORKSPACE%\winbuild\depends\msvcr10-x32
         set BUILD=%GITHUB_WORKSPACE%\winbuild\build
         cd /D %BUILD%\jpeg-9c
-        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform.vars }} 8.1
+        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform-vcvars }} 8.1
         echo on
         nmake -nologo -f makefile.vc setup-vc6
         nmake -nologo -f makefile.vc clean
@@ -61,7 +90,7 @@ jobs:
         set INCLIB=%GITHUB_WORKSPACE%\winbuild\depends\msvcr10-x32
         set BUILD=%GITHUB_WORKSPACE%\winbuild\build
         cd /D %BUILD%\zlib-1.2.11
-        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform.vars }} 8.1
+        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform-vcvars }} 8.1
         echo on
         nmake -nologo -f win32\Makefile.msc clean
         nmake -nologo -f win32\Makefile.msc zlib.lib
@@ -75,7 +104,7 @@ jobs:
         set INCLIB=%GITHUB_WORKSPACE%\winbuild\depends\msvcr10-x32
         set BUILD=%GITHUB_WORKSPACE%\winbuild\build
         cd /D %BUILD%\tiff-4.0.10
-        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform.vars }} 8.1
+        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform-vcvars }} 8.1
         echo on
         copy %GITHUB_WORKSPACE%\winbuild\nmake.opt nmake.opt
         nmake -nologo -f makefile.vc clean
@@ -90,13 +119,13 @@ jobs:
         set INCLIB=%GITHUB_WORKSPACE%\winbuild\depends\msvcr10-x32
         set BUILD=%GITHUB_WORKSPACE%\winbuild\build
         cd /D %BUILD%\libwebp-1.0.3
-        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform.vars }} 8.1
+        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform-vcvars }} 8.1
         echo on
         rmdir /S /Q output\release-static
-        nmake -nologo -f Makefile.vc CFG=release-static RTLIBCFG=static OBJDIR=output ARCH=${{ matrix.platform.name }} all
+        nmake -nologo -f Makefile.vc CFG=release-static RTLIBCFG=static OBJDIR=output ARCH=${{ matrix.architecture }} all
         mkdir %INCLIB%\webp
         copy /Y /B src\webp\*.h %INCLIB%\webp
-        copy /Y /B output\release-static\${{ matrix.platform.name }}\lib\* %INCLIB%
+        copy /Y /B output\release-static\${{ matrix.architecture }}\lib\* %INCLIB%
 
     - name: Build dependencies / freetype
       run: |
@@ -106,16 +135,16 @@ jobs:
         set INCLIB=%GITHUB_WORKSPACE%\winbuild\depends\msvcr10-x32
         set BUILD=%GITHUB_WORKSPACE%\winbuild\build
         cd /D %BUILD%\freetype-2.10.1
-        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform.vars }} 8.1
+        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform-vcvars }} 8.1
         echo on
         rmdir /S /Q objs
         set DefaultPlatformToolset=v140
         set VCTargetsPath=C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\Common7\IDE\VC\VCTargets
         set MSBUILD="C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin\MSBuild.exe"
-        %MSBUILD% builds\windows\vc2010\freetype.sln /t:Build /p:Configuration="Release" /p:Platform=${{ matrix.platform.msbuild }} /m
+        %MSBUILD% builds\windows\vc2010\freetype.sln /t:Build /p:Configuration="Release" /p:Platform=${{ matrix.platform-msbuild }} /m
         xcopy /Y /E /Q include %INCLIB%
-        copy /Y /B objs\${{ matrix.platform.msbuild }}\Release\freetype.dll %INCLIB%
-        copy /Y /B objs\${{ matrix.platform.msbuild }}\Release\freetype.lib %INCLIB%
+        copy /Y /B objs\${{ matrix.platform-msbuild }}\Release\freetype.dll %INCLIB%
+        copy /Y /B objs\${{ matrix.platform-msbuild }}\Release\freetype.lib %INCLIB%
 
     - name: Build dependencies / lcms2
       if: false
@@ -142,7 +171,7 @@ jobs:
         set INCLIB=%GITHUB_WORKSPACE%\winbuild\depends\msvcr10-x32
         set BUILD=%GITHUB_WORKSPACE%\winbuild\build
         cd /D %BUILD%\openjpeg-2.3.1msvcr10-x32
-        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform.vars }} 8.1
+        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform-vcvars }} 8.1
         echo on
         cmake.exe -DBUILD_THIRDPARTY:BOOL=OFF -DBUILD_SHARED_LIBS:BOOL=OFF -DCMAKE_BUILD_TYPE=Release -G "NMake Makefiles" .
         nmake -nologo -f Makefile clean
@@ -157,17 +186,18 @@ jobs:
         set INCLIB=%GITHUB_WORKSPACE%\winbuild\depends\msvcr10-x32
         set BUILD=%GITHUB_WORKSPACE%\winbuild\build
         cd /D %BUILD%\ghostscript-9.27
-        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform.vars }} 8.1
+        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform-vcvars }} 8.1
         echo on
         set MSVC_VERSION=14
         set RCOMP="C:\Program Files (x86)\Microsoft SDKs\Windows\v7.1A\Bin\RC.Exe"
-        if "${{ matrix.platform.name }}"=="x64" set WIN64=""
+        if "${{ matrix.architecture }}"=="x64" set WIN64=""
         nmake -nologo -f psi\msvc.mak
         rem Add bin to PATH variable: Copy to INCLIB, then add INCLIB to PATH in Test step.
         copy /Y /B bin\* %INCLIB%
 
     - name: Build Pillow
       run: |
+        set PYTHON=%pythonLocation%
         set INCLUDE=C:\Program Files (x86)\Microsoft SDKs\Windows\V7.1A\Include
         set MPLSRC=%GITHUB_WORKSPACE%
         set INCLIB=%GITHUB_WORKSPACE%\winbuild\depends\msvcr10-x32
@@ -175,37 +205,30 @@ jobs:
         set DISTUTILS_USE_SDK=1
         set LIB=%INCLIB%;%PYTHON%\tcl
         set INCLUDE=%INCLIB%;%GITHUB_WORKSPACE%\depends\tcl86\include;%INCLUDE%
-        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform.vars }} 8.1
+        call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" ${{ matrix.platform-vcvars }} 8.1
         set BLDOPT=install
         %PYTHON%\%EXECUTABLE% setup.py build_ext --add-imaging-libs=msvcrt install
         %PYTHON%\%EXECUTABLE% -c "from PIL import _webp;import os, shutil;shutil.copy(r'%INCLIB%\freetype.dll', os.path.dirname(_webp.__file__));"
         %PYTHON%\%EXECUTABLE% selftest.py --installed
       env:
-        PYTHON: C:\hostedtoolcache\windows\Python\${{ matrix.python-version }}\${{ matrix.platform.name }}
         EXECUTABLE: python.exe
 
     - name: pip install pytest pytest-cov codecov
-      run: '%PYTHON%\%PIP% install pytest pytest-cov codecov'
-      env:
-        PYTHON: C:\hostedtoolcache\windows\Python\${{ matrix.python-version }}\${{ matrix.platform.name }}
-        PIP: Scripts\pip.exe
+      run: |
+        "%pythonLocation%\python.exe" -m pip install pytest pytest-cov
+        pip install codecov
     
     - name: Test Pillow
       run: |
+        set PYTHON=%pythonLocation%
         set INCLIB=%GITHUB_WORKSPACE%\winbuild\depends\msvcr10-x32
         rem Add GhostScript executables (copied to INCLIB) to PATH.
         path %INCLIB%;%PATH%
         cd /D %GITHUB_WORKSPACE%
-        %PYTHON%\%EXECUTABLE% -m pytest -vx --cov PIL --cov-report term --cov-report xml Tests
-      env:
-        PYTHON: C:\hostedtoolcache\windows\Python\${{ matrix.python-version }}\${{ matrix.platform.name }}
-        EXECUTABLE: python.exe
+        %PYTHON%\python.exe -m pytest -vx --cov PIL --cov-report term --cov-report xml Tests
     
     - name: Upload coverage
-      run: |
-        cd /D %GITHUB_WORKSPACE%
-        %PYTHON%\%CODECOV% --file coverage.xml --name %PYTHON%
+      run: 'codecov --file "%GITHUB_WORKSPACE%\coverage.xml" --name "%pythonLocation%"'
       env:
-        PYTHON: C:\hostedtoolcache\windows\Python\${{ matrix.python-version }}\${{ matrix.platform.name }}
         CODECOV: Scripts\codecov.exe
     
diff --git a/Tests/helper.py b/Tests/helper.py
index 78a2f520f92..c352f54b940 100644
--- a/Tests/helper.py
+++ b/Tests/helper.py
@@ -355,10 +355,17 @@ def on_appveyor():
     return "APPVEYOR" in os.environ
 
 
+def on_github_actions():
+    return "GITHUB_ACTIONS" in os.environ
+
+
 def on_ci():
     # Travis and AppVeyor have "CI"
     # Azure Pipelines has "TF_BUILD"
-    return "CI" in os.environ or "TF_BUILD" in os.environ
+    # GitHub Actions has "GITHUB_ACTIONS"
+    return (
+        "CI" in os.environ or "TF_BUILD" in os.environ or "GITHUB_ACTIONS" in os.environ
+    )
 
 
 if sys.platform == "win32":
diff --git a/Tests/test_image_access.py b/Tests/test_image_access.py
index b06814cb944..b69c2040f4c 100644
--- a/Tests/test_image_access.py
+++ b/Tests/test_image_access.py
@@ -3,7 +3,7 @@
 
 from PIL import Image
 
-from .helper import PillowTestCase, hopper, on_appveyor, unittest
+from .helper import PillowTestCase, hopper, on_ci, unittest
 
 # CFFI imports pycparser which doesn't support PYTHONOPTIMIZE=2
 # https://github.com/eliben/pycparser/pull/198#issuecomment-317001670
@@ -333,8 +333,8 @@ def test_p_putpixel_rgb_rgba(self):
 
 class TestEmbeddable(unittest.TestCase):
     @unittest.skipIf(
-        not sys.platform.startswith("win32") or on_appveyor(),
-        "Failing on AppVeyor when run from subprocess, not from shell",
+        not sys.platform.startswith("win32") or on_ci(),
+        "Failing on AppVeyor / GitHub Actions when run from subprocess, not from shell",
     )
     def test_embeddable(self):
         import subprocess
diff --git a/Tests/test_imageshow.py b/Tests/test_imageshow.py
index 2f2620b7408..bad0329af44 100644
--- a/Tests/test_imageshow.py
+++ b/Tests/test_imageshow.py
@@ -1,6 +1,8 @@
+import sys
+
 from PIL import Image, ImageShow
 
-from .helper import PillowTestCase, hopper, on_ci, unittest
+from .helper import PillowTestCase, hopper, on_ci, on_github_actions, unittest
 
 
 class TestImageShow(PillowTestCase):
@@ -34,7 +36,10 @@ def show_image(self, image, **options):
         # Restore original state
         ImageShow._viewers.pop(0)
 
-    @unittest.skipUnless(on_ci(), "Only run on CIs")
+    @unittest.skipUnless(
+        on_ci() and not (sys.platform == "win32" and on_github_actions()),
+        "Only run on CIs; hangs on Windows on Github Actions",
+    )
     def test_show(self):
         for mode in ("1", "I;16", "LA", "RGB", "RGBA"):
             im = hopper(mode)