diff --git a/.coveragerc b/.coveragerc
index 42c9476a4f0ae7db13a7c422f694e53be1073e08..33dd30c84ddd2e96a947121ac5aae698581cb32c 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -14,3 +14,10 @@ exclude_lines =
     pragma: no cover
     if __name__ == .__main__.:
 
+[paths]
+source =
+    ./
+    C:\GitLab-Runner\builds\*\extensions
+    C:\GitLab-Runner\builds\*\*\extensions
+    C:\builds\*\extensions
+    /builds/*/extensions
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 674ebf97bde34c592a6d09995f97a9b22a5fc236..801d1ad4a5494e7667f6bba29631460627b11d7a 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -21,13 +21,18 @@ variables:
       - .coverage-*
       - htmlcov
 
+.shared-windows-runners:
+  tags:
+    - shared-windows
+    - windows
+    - windows-1809
 
 test:python37:
   extends: .tests
   script:
     - source /root/pyenv-init
     - pyenv shell 3.7.2
-    - tox -e py37-normal
+    - tox -e py37-normal-linux
 
 
 test:python38:
@@ -35,21 +40,34 @@ test:python38:
   script:
     - source /root/pyenv-init
     - pyenv shell 3.8.0
-    - tox -e py38-normal
+    - tox -e py38-normal-linux
 
 test:python39:
   extends: .tests
   script:
     - source /root/pyenv-init
     - pyenv shell 3.9.0
-    - tox -e py39-normal
+    - tox -e py39-normal-linux
+
+test:python38-windows:
+  stage: test
+  extends: 
+    - .shared-windows-runners
+    - .tests
+  script:
+    - choco install python --version 3.8.3 -y -f --no-progress
+    - $env:PATH += ";C:\\PYTHON38\\;C:\\PYTHON38\\Scripts" 
+    - refreshenv
+    - "python -m pip install --upgrade setuptools"
+    - "python -m pip install --upgrade tox"
+    - "tox -e py38-normal-win"
 
 test:python310:
   extends: .tests
   script:
     - source /root/pyenv-init
     - pyenv shell 3.10.0
-    - tox -e py310-normal
+    - tox -e py310-normal-linux
 
 test:coverage:
   stage: coverage
@@ -57,6 +75,7 @@ test:coverage:
     - source /root/pyenv-init
     - pyenv shell 3.7.2
     - pip install coverage
+    - ls -la | grep coverage
     - coverage3 combine .coverage-*
     - coverage3 report -m --precision=2
     - coverage3 html --ignore-errors --title="Coverage for Inkscape Extensions (${CI_COMMIT_REF_NAME} branch)"
@@ -72,6 +91,7 @@ test:coverage:
     - test:python38
     - test:python39
     - test:python310
+    - test:python38-windows
   when: always
   coverage: '/TOTAL.+?(\d+.\d+%)/'
   artifacts:
diff --git a/inkex/command.py b/inkex/command.py
index f1fe260719a46cd0154152397d396c235bbad3ea..d2ff95876973ce7529247b6733be8886f71501ab 100644
--- a/inkex/command.py
+++ b/inkex/command.py
@@ -164,6 +164,9 @@ def to_args(prog, *positionals, **arguments):
     args += [to_arg(pos, oldie) for pos in positionals if pos is not None]
     # Filter out empty non-arguments
     return [arg for arg in args if arg is not None]
+def to_args_sorted(prog, *positionals, **arguments):
+    """same as to_args, but keyword arguments are sorted beforehand"""
+    return to_args(prog, *positionals, **dict(sorted(arguments.items())))
 
 def _call(program, *args, **kwargs):
     stdin = kwargs.pop('stdin', None)
diff --git a/inkex/tester/filters.py b/inkex/tester/filters.py
index c6703716dfeee76a69d4e9c40fa5efa706dedebb..1680350e13ee9e91830ed308892d37cf352fc8b6 100644
--- a/inkex/tester/filters.py
+++ b/inkex/tester/filters.py
@@ -60,7 +60,7 @@ class CompareNumericFuzzy(Compare):
     @staticmethod
     def filter(contents):
         func = lambda m: b'%.3f' % (float(m.group(0)))
-        contents = re.sub(br'\d+\.\d+', func, contents)
+        contents = re.sub(br'\d+\.\d+(e[+-]\d+)?', func, contents)
         contents = re.sub(br'(\d\.\d+?)0+\b', br'\1', contents)
         contents = re.sub(br'(\d)\.0+(?=\D|\b)', br'\1', contents)
         return contents
@@ -138,3 +138,7 @@ class CompareReplacement(Compare):
         for _from, _to in self.deltas:
             contents = contents.replace(to_bytes(_from), to_bytes(_to))
         return contents
+
+class WindowsTextCompat(CompareReplacement):
+    def __init__(self):
+        super().__init__(('\r\n', '\n'))
\ No newline at end of file
diff --git a/inkex/tester/mock.py b/inkex/tester/mock.py
index c6507fe4e60bf6fb1e599b9274cb2e504ecac366..1655fad4450094b08c76e0c7e43612414c8de97b 100644
--- a/inkex/tester/mock.py
+++ b/inkex/tester/mock.py
@@ -174,12 +174,18 @@ class MockCommandMixin(MockMixin):
 
     def clean_paths(self, data, files):
         """Clean a string of any files or tempdirs"""
+        def replace(indata, replaced, replacement):
+            if isinstance(indata, str):
+                indata = indata.replace(replaced, replacement)
+            else:
+                indata = [i.replace(replaced, replacement) for i in indata]
+            return indata
         try:
             for fdir in self.recorded_tempdirs:
-                data = data.replace(fdir, '.')
-                files = [fname.replace(fdir, '.') for fname in files]
+                data = replace(data, fdir, '.')
+                files = replace(files, fdir, '.')
             for fname in files:
-                data = data.replace(fname, os.path.basename(fname))
+                data = replace(data, fname, os.path.basename(fname))
         except (UnicodeDecodeError, TypeError):
             pass
         return data
@@ -205,7 +211,6 @@ class MockCommandMixin(MockMixin):
         if self and program and arglst:
             return os.environ.get('NO_MOCK_COMMANDS')
         return False
-
     def mock_call(self, program, *args, **kwargs):
         """
         Replacement for the inkex.command.call() function, instead of calling
@@ -224,18 +229,20 @@ class MockCommandMixin(MockMixin):
         # may be modified to strip out filename directories (which change)
         inputs, outputs = self.add_call_files(msg, args, kwargs)
 
-        arglst = inkex.command.to_args(program, *args, **kwargs)[1:]
-        arglst.sort()
+        arglst = inkex.command.to_args_sorted(program, *args, **kwargs)[1:]
+        arglst = self.clean_paths(arglst, inputs + outputs)
         argstr = ' '.join(arglst)
-        argstr = self.clean_paths(argstr, inputs + outputs)
         msg['Arguments'] = argstr.strip()
 
         if stdin is not None:
             # The stdin is counted as the msg body
-            cleanin = self.clean_paths(stdin, inputs + outputs)
+            cleanin = self.clean_paths(stdin, inputs + outputs)\
+                          .replace("\r\n", "\n").replace(".\\", "./")
             msg.attach(MIMEText(cleanin, 'plain', 'utf-8'))
 
         keystr = msg.as_string()
+        # On Windows, output is separated by CRLF
+        keystr = keystr.replace('\r\n', '\n')
         # There is a difference between python2 and python3 output
         keystr = keystr.replace('\n\n', '\n')
         keystr = keystr.replace('\n ', ' ')
@@ -273,7 +280,7 @@ class MockCommandMixin(MockMixin):
             self.save_key(program, key, keystr, 'bad-key')
             raise IOError(f"Problem loading call: {program}/{key} use the environment variable "\
                 "NO_MOCK_COMMANDS=1 to call out to the external program and generate "\
-                "the mock call file.")
+                f"the mock call file for call {program} {argstr}.")
 
     def add_call_files(self, msg, args, kwargs):
         """
@@ -316,6 +323,12 @@ class MockCommandMixin(MockMixin):
                 value = self.clean_paths(fhl.read().decode('utf8'), [])
             else:
                 value = fhl.read()
+                try:
+                    value = value.decode()
+                except UnicodeDecodeError: # do not attempt to process binary files further
+                    pass
+            if isinstance(value, str):
+                value = value.replace('\r\n', '\n').replace(".\\", "./")
             part = MIMEApplication(value, Name=fname)
         # After the file is closed
         part['Content-Disposition'] = 'attachment'
diff --git a/inkex/tester/xmldiff.py b/inkex/tester/xmldiff.py
index a3197cfabd7eb03f23d65ea2e66d1cf608fab084..27d672663bfe1b18f45d72934e237f93cb128af4 100644
--- a/inkex/tester/xmldiff.py
+++ b/inkex/tester/xmldiff.py
@@ -41,7 +41,12 @@ class DeltaLogger(list):
                     return [attr] + Path(val).to_arrays()
                 return (attr, val)
             return val
-        self.append((_prep(value_a), _prep(value_b)))
+        # Only append a difference if the preprocessed values are different.
+        # This solves the issue that -0 != 0 in path data.
+        pa = _prep(value_a)
+        pb = _prep(value_b)
+        if pa != pb:
+            self.append((pa, pb))
 
     def append_text(self, text_a, text_b):
         """Record a text difference"""
diff --git a/tar_layers.py b/tar_layers.py
index 09a1dfbd9b9264d88646dba90d2ac46c9d918822..a9ede3d619df050c9f0a5d8ea42dbdc663a7e47a 100755
--- a/tar_layers.py
+++ b/tar_layers.py
@@ -63,7 +63,10 @@ class TarLayers(inkex.OutputExtension):
         # Switch stdout to binary on Windows.
         if sys.platform == "win32":
             import msvcrt
-            msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
+            try:
+                msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
+            except io.UnsupportedOperation:
+                pass # The .fileno() function is not available during pytest runs
 
         template = self.make_template()
 
diff --git a/tests/data/cmd/fig2dev/c15e8c5e5e50d45b2579ac22522b007e.msg b/tests/data/cmd/fig2dev/5d879c5bf2edd4bc478d8bef487538b9.msg
similarity index 100%
rename from tests/data/cmd/fig2dev/c15e8c5e5e50d45b2579ac22522b007e.msg
rename to tests/data/cmd/fig2dev/5d879c5bf2edd4bc478d8bef487538b9.msg
diff --git a/tests/data/cmd/gimp/6c0e5d2fbe380e26e310ebfc206d81ea.msg b/tests/data/cmd/gimp/a8418e80d6e849cc2e91b1baecbfada4.msg
similarity index 100%
rename from tests/data/cmd/gimp/6c0e5d2fbe380e26e310ebfc206d81ea.msg
rename to tests/data/cmd/gimp/a8418e80d6e849cc2e91b1baecbfada4.msg
diff --git a/tests/data/cmd/gimp/9de0e6f5cf782a299a1c062b5412dd63.msg b/tests/data/cmd/gimp/ba387a2bf0dfa5d22b061bfbe6fae05b.msg
similarity index 100%
rename from tests/data/cmd/gimp/9de0e6f5cf782a299a1c062b5412dd63.msg
rename to tests/data/cmd/gimp/ba387a2bf0dfa5d22b061bfbe6fae05b.msg
diff --git a/tests/data/cmd/gswin64c/7379fbc5c4f64c97c911b3e2695fdb8d.msg b/tests/data/cmd/gswin64c/c6b57b05e3a139d2172cab6307ebb2e4.msg
similarity index 96%
rename from tests/data/cmd/gswin64c/7379fbc5c4f64c97c911b3e2695fdb8d.msg
rename to tests/data/cmd/gswin64c/c6b57b05e3a139d2172cab6307ebb2e4.msg
index ed7676c87f314c54b8d9a5d1efc8aae258c01fdc..740011b7e2b82c1abe79ff727239cb596a2bf136 100644
--- a/tests/data/cmd/gswin64c/7379fbc5c4f64c97c911b3e2695fdb8d.msg
+++ b/tests/data/cmd/gswin64c/c6b57b05e3a139d2172cab6307ebb2e4.msg
@@ -1,7 +1,7 @@
 Content-Type: multipart/mixed; boundary="--CALLDATA--//--CALLDATA--"
 MIME-Version: 1.0
 Program: gswin64c
-Arguments: -P- -dBATCH -dCompatibilityLevel#1.4 -dNOPAUSE -dSAFER -q -sDEVICE#pdfwrite -sOutputFile#.\output.pdf test.eps
+Arguments: -q -P- -dSAFER -dNOPAUSE -dBATCH -sDEVICE#pdfwrite -dCompatibilityLevel#1.4 -sOutputFile#.\output.pdf test.eps
 
 ----CALLDATA--//--CALLDATA--
 Content-Type: application/octet-stream; Name="output.pdf"
diff --git a/tests/data/cmd/gswin64c/685cf0650d5e5573b3bc5bbeafbc2a7a.msg b/tests/data/cmd/gswin64c/f016f18bc5ee9c06cbf8bd0e05d54648.msg
similarity index 96%
rename from tests/data/cmd/gswin64c/685cf0650d5e5573b3bc5bbeafbc2a7a.msg
rename to tests/data/cmd/gswin64c/f016f18bc5ee9c06cbf8bd0e05d54648.msg
index 20063c0ea9822ac1e1f186248cd2ec0b77e92e51..78ab4eefc643824bb2fa5dab9d256e4f11b28bd3 100644
--- a/tests/data/cmd/gswin64c/685cf0650d5e5573b3bc5bbeafbc2a7a.msg
+++ b/tests/data/cmd/gswin64c/f016f18bc5ee9c06cbf8bd0e05d54648.msg
@@ -1,7 +1,7 @@
 Content-Type: multipart/mixed; boundary="--CALLDATA--//--CALLDATA--"
 MIME-Version: 1.0
 Program: gswin64c
-Arguments: -P- -dBATCH -dCompatibilityLevel#1.4 -dNOPAUSE -dSAFER -q -sDEVICE#pdfwrite -sOutputFile#.\output.pdf test.ps
+Arguments: -q -P- -dSAFER -dNOPAUSE -dBATCH -sDEVICE#pdfwrite -dCompatibilityLevel#1.4 -sOutputFile#.\output.pdf test.ps
 
 ----CALLDATA--//--CALLDATA--
 Content-Type: application/octet-stream; Name="output.pdf"
diff --git a/tests/data/cmd/inkscape/f863b882b18ffd8659b3c20cdd549266.msg b/tests/data/cmd/inkscape/1c734cd0171b9097039996e1bd63ed6f.msg
similarity index 100%
rename from tests/data/cmd/inkscape/f863b882b18ffd8659b3c20cdd549266.msg
rename to tests/data/cmd/inkscape/1c734cd0171b9097039996e1bd63ed6f.msg
diff --git a/tests/data/cmd/inkscape/818d4c30d07def36e80e32df12023124.msg b/tests/data/cmd/inkscape/21e5197995b5aa619151b61ebee79f23.msg
similarity index 100%
rename from tests/data/cmd/inkscape/818d4c30d07def36e80e32df12023124.msg
rename to tests/data/cmd/inkscape/21e5197995b5aa619151b61ebee79f23.msg
diff --git a/tests/data/cmd/inkscape/581055ce0e3ef5df0c1ab22982a51513.msg b/tests/data/cmd/inkscape/7f8bea1476711ae5f57b9d30111ec50b.msg
similarity index 100%
rename from tests/data/cmd/inkscape/581055ce0e3ef5df0c1ab22982a51513.msg
rename to tests/data/cmd/inkscape/7f8bea1476711ae5f57b9d30111ec50b.msg
diff --git a/tests/data/cmd/inkscape/c23825a5b83e906138ca8bff105b8b29.msg b/tests/data/cmd/inkscape/bf3e6cfcbb81940d4f7d667750681b0c.msg
similarity index 100%
rename from tests/data/cmd/inkscape/c23825a5b83e906138ca8bff105b8b29.msg
rename to tests/data/cmd/inkscape/bf3e6cfcbb81940d4f7d667750681b0c.msg
diff --git a/tests/data/cmd/scribus/b8a765f070200c63d022a696ac129e35.msg b/tests/data/cmd/scribus/cbaa8e934937d1d6b0355b525b5351e5.msg
similarity index 100%
rename from tests/data/cmd/scribus/b8a765f070200c63d022a696ac129e35.msg
rename to tests/data/cmd/scribus/cbaa8e934937d1d6b0355b525b5351e5.msg
diff --git a/tests/data/cmd/scribus/a5ed3ec8aa6d61652cb04fa27f921943.msg b/tests/data/cmd/scribus/e1f8033066a1e79d574f64111d5b92af.msg
similarity index 100%
rename from tests/data/cmd/scribus/a5ed3ec8aa6d61652cb04fa27f921943.msg
rename to tests/data/cmd/scribus/e1f8033066a1e79d574f64111d5b92af.msg
diff --git a/tests/test_color_list.py b/tests/test_color_list.py
index 6f38e6ddf47a6c1b7a667ed5742c6d47bf20bfc9..c05f6469a7570031e7d45dcddd66d95ec61118d9 100644
--- a/tests/test_color_list.py
+++ b/tests/test_color_list.py
@@ -1,9 +1,11 @@
 # coding=utf-8
 from color_list import ListColours
 from .test_inkex_extensions import ColorEffectTest
+from inkex.tester.filters import WindowsTextCompat
 
 class ColorListTest(ColorEffectTest):
     effect_class = ListColours
     effect_name = 'test_color_list'
     stderr_output = True
+    compare_filters = [WindowsTextCompat()]
     color_tests = []
diff --git a/tests/test_docinfo.py b/tests/test_docinfo.py
index 1390d5b77cc46eac95924b63c215e2da795c1e7a..324b4b90f7ec151b360603b424f2ab5097d3c167 100644
--- a/tests/test_docinfo.py
+++ b/tests/test_docinfo.py
@@ -1,9 +1,11 @@
 # coding=utf-8
 from docinfo import DocInfo
 from inkex.tester import ComparisonMixin, TestCase
+from inkex.tester.filters import WindowsTextCompat
 
 class TestDocInfo(ComparisonMixin, TestCase):
     compare_file = 'svg/guides.svg'
     effect_class = DocInfo
     stderr_output = True
     comparisons = [()]
+    compare_filters = [WindowsTextCompat()]
\ No newline at end of file
diff --git a/tests/test_dxf12_outlines.py b/tests/test_dxf12_outlines.py
index e1bb05013865171e3c419d9a4f0205ecffd90b32..6bf8198334aadef31258326cd533e25ee9889836 100644
--- a/tests/test_dxf12_outlines.py
+++ b/tests/test_dxf12_outlines.py
@@ -1,10 +1,11 @@
 # coding=utf-8
 from dxf12_outlines import DxfTwelve
 from inkex.tester import ComparisonMixin, TestCase
-
+from inkex.tester.filters import WindowsTextCompat
 
 class TestDXF12OutlinesBasic(ComparisonMixin, TestCase):
     compare_file = ["svg/shapes.svg", "svg/preserved-transforms.svg",
                     "svg/dxf_nested_transforms.svg"]
     comparisons = [()]
-    effect_class = DxfTwelve
\ No newline at end of file
+    effect_class = DxfTwelve
+    compare_filters = [WindowsTextCompat()]
\ No newline at end of file
diff --git a/tests/test_dxf_outlines.py b/tests/test_dxf_outlines.py
index 76a235097e45c41ee1248219fb2ef8a341eecca1..f830d23cd1673caf57283a46153933db5b1658c5 100644
--- a/tests/test_dxf_outlines.py
+++ b/tests/test_dxf_outlines.py
@@ -1,7 +1,7 @@
 # coding=utf-8
 from dxf_outlines import DxfOutlines
 from inkex.tester import ComparisonMixin, InkscapeExtensionTestMixin, TestCase
-
+from inkex.tester.filters import WindowsTextCompat
 
 class DFXOutlineBasicTest(ComparisonMixin, InkscapeExtensionTestMixin, TestCase):
     effect_class = DxfOutlines
@@ -11,3 +11,4 @@ class DFXOutlineBasicTest(ComparisonMixin, InkscapeExtensionTestMixin, TestCase)
         ('--POLY=true',),
         ('--ROBO=true',),
     ]
+    compare_filters = [WindowsTextCompat()]
diff --git a/tests/test_export_gimp_palette.py b/tests/test_export_gimp_palette.py
index c322b313a98083fa879d9a7f1f86d7c8db3c1331..9f0c977219e88cbe517812e387ca30b0ec604dbe 100644
--- a/tests/test_export_gimp_palette.py
+++ b/tests/test_export_gimp_palette.py
@@ -1,7 +1,9 @@
 # coding=utf-8
 from export_gimp_palette import ExportGimpPalette
 from inkex.tester import ComparisonMixin, TestCase
+from inkex.tester.filters import WindowsTextCompat
 
 class TestExportGplBasic(ComparisonMixin, TestCase):
     effect_class = ExportGimpPalette
     compare_file = 'svg/colors.svg'
+    compare_filters = [WindowsTextCompat()]
\ No newline at end of file
diff --git a/tests/test_ink2canvas_svg.py b/tests/test_ink2canvas_svg.py
index d3e3270c7ea955c4879d6a65c06f9a9e9a5b3b69..3401db417dc0c4ff07eabc095b703e88b38f1d59 100644
--- a/tests/test_ink2canvas_svg.py
+++ b/tests/test_ink2canvas_svg.py
@@ -3,6 +3,7 @@
 from ink2canvas import Html5Canvas
 from inkex.tester import ComparisonMixin, TestCase
 from inkex.tester.filters import CompareOrderIndependentLines
+from inkex.tester.filters import WindowsTextCompat
 
 class Ink2CanvasBasicTest(ComparisonMixin, TestCase):
     effect_class = Html5Canvas
@@ -21,4 +22,5 @@ class Ink2CanvasTestTextPath(ComparisonMixin, TestCase):
 class Ink2CanvasTestClosedPath(ComparisonMixin, TestCase):
     effect_class = Html5Canvas
     compare_file = 'svg/multiple_closed_subpaths.svg'
-    comparisons = [("--id=path31",)]
\ No newline at end of file
+    comparisons = [("--id=path31",)]
+    compare_filters = [WindowsTextCompat()]
\ No newline at end of file
diff --git a/tests/test_inkex_base.py b/tests/test_inkex_base.py
index 01fe619bd2d16ce700d79b7eadf6c01f80b9f3f3..44cacd33c63eacecea8154c915a2470bcf974e03 100644
--- a/tests/test_inkex_base.py
+++ b/tests/test_inkex_base.py
@@ -99,7 +99,7 @@ class InkscapeExtensionTest(TestCase):
         ext = ModExtension()
         os.environ['DOCUMENT_PATH'] = self.empty_svg
         self.assertEqual(ext.svg_path(), os.path.join(self.datadir(), 'svg'))
-        self.assertEqual(ext.absolute_href('/foo'), '/foo')
+        self.assertIn(ext.absolute_href('/foo'), ['/foo', "C:\\foo"])
         self.assertEqual(ext.absolute_href('./foo'), os.path.join(self.datadir(), 'svg', 'foo'))
         self.assertEqual(ext.absolute_href('~/foo'), os.path.realpath(os.path.expanduser('~/foo')))
 
diff --git a/tests/test_inkex_command.py b/tests/test_inkex_command.py
index dd60357ace1adb56c2054bcb31d8052e04bb80db..ed271a8f86b5199349a616350e48c410f16b79a4 100644
--- a/tests/test_inkex_command.py
+++ b/tests/test_inkex_command.py
@@ -2,12 +2,14 @@
 """
 Test Inkex command launching functionality.
 """
-
+import pytest
+import sys
 from inkex.tester import BaseCase
 from inkex.command import which, write_svg, to_arg, to_args, call, inkscape, inkscape_command, take_snapshot
 
 class CommandTest(BaseCase):
     """Test command API"""
+    @pytest.mark.skipif(sys.platform=="win32", reason="gunzip doesn't exist on windows")
     def test_binary_call(self):
         """Calls should allow binary stdin"""
         # https://gitlab.com/inkscape/extensions/-/commit/2e504f2a3f6bb627f17b267c5623a71005d7234d#note_164780678
diff --git a/tests/test_inkex_deprecated.py b/tests/test_inkex_deprecated.py
index b569a7684975178f948e0886493810acbc3dcc23..546f158a1b7c9671133b59a45376a7b260dfd721 100644
--- a/tests/test_inkex_deprecated.py
+++ b/tests/test_inkex_deprecated.py
@@ -1,7 +1,7 @@
 # coding=utf-8
 """Test base inkex module functionality"""
 from __future__ import absolute_import, print_function, unicode_literals
-
+from pathlib import Path
 import warnings
 
 from inkex.deprecated import _deprecated
@@ -32,5 +32,5 @@ class DeprecatedTests(TestCase):
     def test_traceback(self):
         """Traceback is possible for deprecation warnings"""
         warn = self.assertDeprecated(_deprecated, False, "BAR", stack=0, level=2)
-        self.assertIn("inkex/deprecated.py", str(warn.message))
+        self.assertIn(str(Path("inkex") / "deprecated"), str(warn.message))
         self.assertIn("test_inkex_deprecated.py", str(warn.message))
diff --git a/tests/test_jessyink_summary.py b/tests/test_jessyink_summary.py
index 45c3a526648d39172add9dd14a61f702c07ef085..4a881dfa86a8643c928f4331c63bbc5ea0cf48f7 100644
--- a/tests/test_jessyink_summary.py
+++ b/tests/test_jessyink_summary.py
@@ -1,8 +1,10 @@
 # coding=utf-8
 from jessyink_summary import Summary
 from inkex.tester import ComparisonMixin, TestCase
+from inkex.tester.filters import WindowsTextCompat
 
 class JessyInkSummaryTest(ComparisonMixin, TestCase):
     stderr_output = True
     effect_class = Summary
     comparisons = [()]
+    compare_filters = [WindowsTextCompat()]
diff --git a/tests/test_plotter.py b/tests/test_plotter.py
index 2d05ba365701bcf572bb066e5f229958579ffd12..d24a707268e7ab356a0cee106f7abf632bc2f2bf 100644
--- a/tests/test_plotter.py
+++ b/tests/test_plotter.py
@@ -1,8 +1,11 @@
 """Test Plotter extension"""
+import pytest
+import sys
 from plotter import Plot
 from inkex.tester import ComparisonMixin, TestCase
 from inkex.tester.filters import CompareReplacement
 
+@pytest.mark.skipif(sys.platform == "win32", reason="termios not available on Windows")
 class TestPlotter(ComparisonMixin, TestCase):
     """Test the plotter extension"""
     stderr_output = True
diff --git a/tests/test_polyhedron_3d.py b/tests/test_polyhedron_3d.py
index 4c26ace05cdd1aaf1720c4b95a4906a89bb6c7cb..5fa315ec47d65777a2703c435b129fd7e3cc4fd3 100644
--- a/tests/test_polyhedron_3d.py
+++ b/tests/test_polyhedron_3d.py
@@ -1,6 +1,7 @@
 # coding=utf-8
 from polyhedron_3d import Poly3D
 from inkex.tester import ComparisonMixin, TestCase
+from inkex.tester.filters import CompareNumericFuzzy
 
 class Poly3DBasicTest(ComparisonMixin, TestCase):
     effect_class = Poly3D
@@ -15,4 +16,5 @@ class Poly3DBasicTest(ComparisonMixin, TestCase):
         ('--show=edg', '--obj=methane', '--cw_wound=True'),
         ('--show=fce', '--obj=from_file', '--spec_file=great_stel_dodec.obj', '--cw_wound=True'),
     ]
+    compare_filters = [CompareNumericFuzzy()]
     compare_file = 'svg/empty.svg'
diff --git a/tests/test_replace_font.py b/tests/test_replace_font.py
index cbd68c4b8ba5b5aa0e7c20cd466400506ebb9b08..ea1ed5c81c555589d3fedf483055424f9655a7e3 100644
--- a/tests/test_replace_font.py
+++ b/tests/test_replace_font.py
@@ -2,6 +2,7 @@
 from replace_font import ReplaceFont
 from inkex.tester import ComparisonMixin, InkscapeExtensionTestMixin, TestCase
 from inkex.tester.filters import CompareOrderIndependentStyle
+from inkex.tester.filters import WindowsTextCompat
 
 class TestReplaceFontBasic(ComparisonMixin, InkscapeExtensionTestMixin, TestCase):
     effect_class = ReplaceFont
@@ -16,3 +17,4 @@ class TestFontList(ComparisonMixin, TestCase):
     effect_class = ReplaceFont
     comparisons = [('--action=list_only',),]
     stderr_output = True
+    compare_filters = [WindowsTextCompat()]
diff --git a/tests/test_text_extract.py b/tests/test_text_extract.py
index 11ddec47ce0c77bd202c56de385fcbb2733992d0..63f6e582fa0c4464013d2fae342141b43e7d5ac1 100644
--- a/tests/test_text_extract.py
+++ b/tests/test_text_extract.py
@@ -1,6 +1,7 @@
 # coding=utf-8
 from inkex.tester import ComparisonMixin, TestCase
 from text_extract import Extract
+from inkex.tester.filters import WindowsTextCompat
 
 class TestExtractBasic(ComparisonMixin, TestCase):
     effect_class = Extract
@@ -11,3 +12,4 @@ class TestExtractBasic(ComparisonMixin, TestCase):
         ('--direction=lr', '--xanchor=center_x', '--yanchor=center_y'),
         ('--direction=rl', '--xanchor=center_x', '--yanchor=center_y'),
     ]
+    compare_filters = [WindowsTextCompat()]
diff --git a/tox.ini b/tox.ini
index 3e7a040b2251213b15ea553214cbc58bff7d3ed8..e570084e2a80ce7f7392e62bb2e9d22f460f9ca3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,9 +1,15 @@
 [tox]
-envlist = py{36,37,38,39,310}-normal
+envlist = py{36,37,38,39,310}-normal-{linux,win}
 
 
 [testenv]
-setenv = COVERAGE_FILE=.coverage-{env:TOX_ENV_NAME}
+platform =
+    linux: linux
+    win: win32
+
+setenv = 
+    COVERAGE_FILE=.coverage-{env:TOX_ENV_NAME}
+    win: COVERAGE_FILE=.coverage-{env:TOX_ENV_NAME}-win
 
 commands =
     pytest --ignore=other --cov=. --cov-report html --cov-report term {posargs}
@@ -12,4 +18,11 @@ deps =
     -rtests/dev_requirements.txt
 
 [pytest]
-addopts = --ignore=other --cov=. --cov-report=xml
+addopts = --ignore=other
+
+[coverage3:paths]
+source =
+    C:\GitLab-Runner\builds\*\extensions
+    C:\GitLab-Runner\builds\*\*\extensions
+    C:\builds\*\extensions
+    /builds/*/extensions
diff --git a/webslicer_export.py b/webslicer_export.py
index 1c718d8619f91d75c3ccff632550cfb5ed76f170..578cf26df71a0214becdbf9d423f1d1956199ed9 100755
--- a/webslicer_export.py
+++ b/webslicer_export.py
@@ -16,6 +16,7 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #
+import subprocess
 import os
 import sys
 import tempfile
@@ -61,21 +62,17 @@ class Export(WebSlicerMixin, inkex.OutputExtension):
         return None
 
     def get_cmd_output(self, cmd):
-        # This solution comes from Andrew Reedick <jr9445 at ATT.COM>
-        # http://mail.python.org/pipermail/python-win32/2008-January/006606.html
-        # This method replaces the commands.getstatusoutput() usage, with the
-        # hope to correct the windows exporting bug:
-        # https://bugs.launchpad.net/inkscape/+bug/563722
-        if sys.platform != "win32":
-            cmd = '{ ' + cmd + '; }'
-        pipe = os.popen(cmd + ' 2>&1', 'r')
-        text = pipe.read()
-        sts = pipe.close()
+        try:
+            pipe = subprocess.Popen(cmd)
+        except FileNotFoundError:
+            return 1, ""
+        stdout, _ = pipe.communicate()
+        sts = pipe.returncode
         if sts is None:
             sts = 0
-        if text[-1:] == '\n':
-            text = text[:-1]
-        return sts, text
+        if stdout is not None and stdout[-1:] == '\n':
+            stdout = stdout[:-1]
+        return sts, stdout
 
     _html_ids = []