diff --git a/changelog.d/7703.misc b/changelog.d/7703.misc
new file mode 100644
index 0000000000000000000000000000000000000000..6e89897e455f6e904aa36b2e80cba9345c6cf8aa
--- /dev/null
+++ b/changelog.d/7703.misc
@@ -0,0 +1 @@
+Make Tox actions work on Debian 10.
diff --git a/tox.ini b/tox.ini
index 463a34d13776912a75bb926511523a4061658bbb..812fbff200d844f298546f56faecd33b7b2f4609 100644
--- a/tox.ini
+++ b/tox.ini
@@ -2,7 +2,6 @@
 envlist = packaging, py35, py36, py37, py38, check_codestyle, check_isort
 
 [base]
-basepython = python3.7
 deps =
     mock
     python-subunit
@@ -120,11 +119,11 @@ commands =
 
 [testenv:check_codestyle]
 skip_install = True
-basepython = python3.6
 deps =
     flake8
     flake8-comprehensions
-    black==19.10b0  # We pin so that our tests don't start failing on new releases of black.
+    # We pin so that our tests don't start failing on new releases of black.
+    black==19.10b0
 commands =
     python -m black --check --diff .
     /bin/sh -c "flake8 synapse tests scripts scripts-dev synctl {env:PEP8SUFFIX:}"
@@ -140,7 +139,6 @@ skip_install = True
 deps = towncrier>=18.6.0rc1
 commands =
    python -m towncrier.check --compare-with=origin/develop
-basepython = python3.6
 
 [testenv:check-sampleconfig]
 commands = {toxinidir}/scripts-dev/generate_sample_config --check