diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 67ff683..c590769 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -24,11 +24,10 @@ jobs:
       - name: Install the project and dependencies
         run: uv sync --all-extras
 
-      # - uses: astral-sh/ruff-action@v3
+      - uses: astral-sh/ruff-action@v3
 
       - name: Run tests with coverage
-        run: uv run pytest tests
+        run: uv run coverage run -m pytest
 
-      # TODO: figure out how to use this
-      # - name: Produce coverage report
-      #   run: uv run coverage report -m
\ No newline at end of file
+      - name: Produce coverage report
+        run: uv run coverage report -m
diff --git a/pyproject.toml b/pyproject.toml
index 6123d37..d01eb0e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,7 +39,7 @@ Homepage = "https://github.com/tmcclintock/ConditionalGMM"
 Issues = "https://github.com/tmcclintock/ConditionalGMM/issues"
 
 [tool.coverage.run]
-include = ["./ConditionalGMM/*"]
+include = ["./src/ConditionalGMM/*"]
 omit = [
   "*tests*",
   "*__init__*"
@@ -52,3 +52,8 @@ exclude_lines = [
   "if __name__ == .__main__.:",
   "@tf.function"
 ]
+
+[dependency-groups]
+dev = [
+    "ruff>=0.11.9",
+]
diff --git a/src/ConditionalGMM/UnivariateGMM.py b/src/ConditionalGMM/UnivariateGMM.py
index 104c217..52fb14e 100644
--- a/src/ConditionalGMM/UnivariateGMM.py
+++ b/src/ConditionalGMM/UnivariateGMM.py
@@ -103,8 +103,9 @@ def ppf(self, q):
             (float or array-like) quantile corresponding to `q`
 
         """
-        f = lambda x: self.cdf(x) - q
-        return sp.optimize.newton(func=f, x0=self.mean(), fprime=self.pdf)
+        return sp.optimize.newton(
+            func=lambda x: self.cdf(x) - q, x0=self.mean(), fprime=self.pdf
+        )
 
     def mean(self):
         """Mean of the RV for the GMM.
diff --git a/tests/test_cGMM.py b/tests/test_cGMM.py
index 91fe927..e46bf00 100644
--- a/tests/test_cGMM.py
+++ b/tests/test_cGMM.py
@@ -14,7 +14,7 @@ def test_cGMM_basic():
     means = [[0.5, -0.2]]
     covs = [[[2.0, 0.3], [0.3, 0.5]]]
     fixed_inds = [1]
-    cGMM = CondGMM(weights, means, covs, fixed_inds)
+    CondGMM(weights, means, covs, fixed_inds)
 
     # 2d - 2 component
     weights = [0.5, 0.5]
diff --git a/tests/test_cMVN.py b/tests/test_cMVN.py
index e152b9f..fd8cb87 100644
--- a/tests/test_cMVN.py
+++ b/tests/test_cMVN.py
@@ -13,20 +13,19 @@ def test_cMN_basic():
     means = [0.5, -0.2]
     cov = [[2.0, 0.3], [0.3, 0.5]]
     ind = [0]
-    cMN = CondMNorm(means, cov, ind)
+    CondMNorm(means, cov, ind)
 
     # 3D
     means = [0.5, -0.2, 1.0]
     cov = [[2.0, 0.3, 0.0], [0.3, 0.5, 0.0], [0.0, 0.0, 1.0]]
     inds = [1, 2]
-    cMN = CondMNorm(means, cov, inds)
+    CondMNorm(means, cov, inds)
 
 
 def test_cMN_exceptions():
     # 3D
     means = [0.5, -0.2, 1.0]
     cov = [[2.0, 0.3, 0.0], [0.3, 0.5, 0.0], [0.0, 0.0, 1.0]]
-    inds = [1, 2]
 
     with pytest.raises(AssertionError):
         CondMNorm(means, cov, [-1])