diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index b3505f831..5631a58a4 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -4,6 +4,9 @@ Jupytext ChangeLog
 1.13.4-dev (2021-12-??)
 -----------------------
 
+**Changed**
+- The test suite turns warnings into errors, after filtering the warnings that don't belong to Jupytext ([#823](https://github.com/mwouts/jupytext/issues/823))
+
 **Fixed**
 - The parsing of notebooks that don't have a YAML header (like `docs/formats.md`) was improved.
 - The test suite works with `pytest-randomly` ([#838](https://github.com/mwouts/jupytext/issues/838))
diff --git a/pyproject.toml b/pyproject.toml
index 87eef4f66..907ad6dcf 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,3 +1,21 @@
 [build-system]
 requires = ["jupyter_packaging~=0.7.9", "jupyterlab>=3.0.0,==3.*", "setuptools>=40.8.0", "wheel"]
 build-backend = "setuptools.build_meta"
+[tool.pytest.ini_options]
+filterwarnings = [
+    # Uncomment this "error" to turn all unfiltered warnings into errors
+    "error",
+    # use single quote to denote raw strings in toml
+    'ignore:Passing unrecognized arguments to super\(KernelSpec\).__init__:DeprecationWarning',
+    # In many tests
+    "ignore:Passing a schema to Validator.iter_errors is deprecated and will be removed in a future release:DeprecationWarning",
+    # in test_utf8_out_331 and two others
+    'ignore:Exception ignored in. <function Context.__del__:pytest.PytestUnraisableExceptionWarning',
+    'ignore:.*contextfilter.* renamed to .*pass_context:DeprecationWarning',
+    # in test_cli_expect_errors and two others
+    'ignore:Exception ignored in. <socket.socket:pytest.PytestUnraisableExceptionWarning',
+    # test_config_jupytext_jupyter_fs_meta_manager
+    'ignore:The alias `_\(\)` will be deprecated. Use `_i18n\(\)` instead.:FutureWarning',
+    # Conda/Python 3.7/Windows - ImportError while loading conftest
+    "ignore:the imp module is deprecated in favour of importlib:DeprecationWarning"
+]
diff --git a/tests/test_cli.py b/tests/test_cli.py
index c03cdd4a5..68e243519 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -67,6 +67,7 @@ def test_convert_single_file_in_place(nb_file, tmpdir):
     compare_notebooks(nb2, nb1)
 
 
+@requires_jupytext_installed
 def test_convert_single_file_in_place_m(tmpdir):
     nb_file = list_notebooks("ipynb_py")[0]
     nb_org = str(tmpdir.join(os.path.basename(nb_file)))
@@ -687,6 +688,7 @@ def test_set_kernel_works_with_pipes_326(capsys):
 
 
 @skip_on_windows
+@pytest.mark.filterwarnings("ignore")
 def test_utf8_out_331(capsys, caplog):
     py = u"from IPython.core.display import HTML; HTML(u'\xd7')"
 
@@ -703,6 +705,7 @@ def test_utf8_out_331(capsys, caplog):
 
 
 @requires_jupytext_installed
+@pytest.mark.filterwarnings("ignore:The --pre-commit argument is deprecated")
 def test_cli_expect_errors(tmp_ipynb):
     with pytest.raises(ValueError):
         jupytext([])
@@ -722,6 +725,11 @@ def test_cli_expect_errors(tmp_ipynb):
         system("jupytext", ["notebook.ipynb", "--from", "py:percent", "--to", "md"])
 
 
+@pytest.mark.filterwarnings(
+    "ignore:You have passed a file name to the '--to' option, "
+    "when a format description was expected. "
+    "Maybe you want to use the '-o' option instead?"
+)
 def test_format_prefix_suffix(tmpdir, cwd_tmpdir):
     os.makedirs("notebooks")
     tmp_ipynb = "notebooks/notebook_name.ipynb"
@@ -788,9 +796,12 @@ def test_cli_sync_file_with_suffix(tmpdir, cwd_tmpdir):
     jupytext(["--sync", tmp_lgt_py])
     jupytext(["--sync", tmp_ipynb])
 
-    assert open(tmp_lgt_py).read().splitlines()[-2:] == ["", "1+1"]
-    assert open(tmp_pct_py).read().splitlines()[-3:] == ["", "# %%", "1+1"]
-    assert open(tmp_rmd).read().splitlines()[-4:] == ["", "```{python}", "1+1", "```"]
+    with open(tmp_lgt_py) as fp:
+        assert fp.read().splitlines()[-2:] == ["", "1+1"]
+    with open(tmp_pct_py) as fp:
+        fp.read().splitlines()[-3:] == ["", "# %%", "1+1"]
+    with open(tmp_rmd) as fp:
+        fp.read().splitlines()[-4:] == ["", "```{python}", "1+1", "```"]
 
 
 @requires_sphinx_gallery
diff --git a/tests/test_cm_config.py b/tests/test_cm_config.py
index c81d752c4..7bbb48e0c 100644
--- a/tests/test_cm_config.py
+++ b/tests/test_cm_config.py
@@ -87,6 +87,10 @@ def test_pairing_through_config_leaves_ipynb_unmodified(tmpdir):
         (".jupytext.py", "c.hide_notebook_metadata = true"),
     ],
 )
+@pytest.mark.filterwarnings(
+    r"ignore:Passing (unrecognized|unrecoginized) arguments "
+    r"to super\(JupytextConfiguration\).__init__"
+)
 def test_incorrect_config_message(tmpdir, cfg_file, cfg_text):
     cm = jupytext.TextFileContentsManager()
     cm.root_dir = str(tmpdir)
diff --git a/tests/test_pre_commit_scripts.py b/tests/test_pre_commit_scripts.py
index ce545be60..b70514fc1 100644
--- a/tests/test_pre_commit_scripts.py
+++ b/tests/test_pre_commit_scripts.py
@@ -262,6 +262,7 @@ def test_pre_commit_hook_sync_black_flake8(tmpdir, nb_file):
         git("commit", "-m", "created")
 
 
+@pytest.mark.filterwarnings("ignore:The --pre-commit argument is deprecated")
 def test_manual_call_of_pre_commit_hook(tmpdir):
     tmp_ipynb = str(tmpdir.join("notebook.ipynb"))
     tmp_py = str(tmpdir.join("notebook.py"))