diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 7e93f9e68..153c7bf89 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -59,6 +59,7 @@ jobs:
     - run: flake8
     - run: ufmt check .
     - run: python3 -m fixit.cli.run_rules
+    - run: python -m slotscheck libcst
 
 # Run pyre typechecker
   typecheck:
diff --git a/README.rst b/README.rst
index be1d5d94a..946168327 100644
--- a/README.rst
+++ b/README.rst
@@ -164,6 +164,13 @@ changes to be conformant, run the following in the root:
 
     ufmt format && python -m fixit.cli.apply_fix
 
+We use `slotscheck <https://slotscheck.rtfd.io>`_ to check the correctness
+of class ``__slots__``. To check that slots are defined properly, run:
+
+.. code-block:: shell
+
+    python -m slotscheck libcst
+
 To run all tests, you'll need to do the following in the root:
 
 .. code-block:: shell
diff --git a/pyproject.toml b/pyproject.toml
index 1d33e75e0..84cfc6282 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,5 +5,8 @@ exclude = "native/.*"
 [tool.ufmt]
 excludes = ["native/", "stubs/"]
 
+[tool.slotscheck]
+exclude-modules = '^libcst\.(testing|tests)'
+
 [build-system]
 requires = ["setuptools", "wheel", "setuptools-rust"]
\ No newline at end of file
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 388c7556b..dbebc1850 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -15,3 +15,4 @@ sphinx-rtd-theme>=0.4.3
 ufmt==1.3
 usort==1.0.0rc1
 setuptools-rust>=0.12.1
+slotscheck>=0.7.1