diff --git a/.github/workflows/typecheck.yml b/.github/workflows/typecheck.yml
index 806d0b01..f062e4e2 100644
--- a/.github/workflows/typecheck.yml
+++ b/.github/workflows/typecheck.yml
@@ -30,7 +30,7 @@ jobs:
           version: 'latest'
 
       - name: Install dependencies
-        run: uv sync --all-extras
+        run: uv sync --extra dev,llm,dataframe
 
       - name: Run mypy
         run: |
diff --git a/changelog.md b/changelog.md
index 6ae5b448..964bb365 100644
--- a/changelog.md
+++ b/changelog.md
@@ -27,6 +27,7 @@ Internal
 * Use the `uv` outside of the `tox` environment when testing.
 * Use forward-slash forms of special commands in the behave test suite.
 * Use forward-slash forms of special commands in the pytest test suite.
+* Add a `tox` typecheck command.
 
 
 v2.27.0 (2026/09/29)
diff --git a/pyproject.toml b/pyproject.toml
index b0d1a159..76480172 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -164,6 +164,11 @@ deps = ['ruff']
 commands = [['ruff', 'check'],
             ['ruff', 'format', '--diff']]
 
+[tool.tox.env.typecheck]
+skip_install = true
+commands = [['uv', 'run', '--no-sync', '--frozen', '--', 'python', '-m', 'ensurepip'],
+            ['uv', 'run', '--no-sync', '--frozen', '--', 'python', '-m', 'mypy', '--no-pretty', '--install-types', '--non-interactive', '.']]
+
 [tool.pytest]
 addopts = ['--random-order']