diff --git a/tests/backends/ott/test_backend.py b/tests/backends/ott/test_backend.py
index 31287975..b268bdb3 100644
--- a/tests/backends/ott/test_backend.py
+++ b/tests/backends/ott/test_backend.py
@@ -351,7 +351,9 @@ def test_pull(
         xx, yy = xy
         solver = solver_t()
         additional_kwargs = {"alpha": 1.0} if xy is None else {}
-        out = solver(a=jnp.ones(len(x)) / len(x), b=jnp.ones(len(y)) / len(y), x=x, y=y, xy=(xx, yy), **additional_kwargs)
+        out = solver(
+            a=jnp.ones(len(x)) / len(x), b=jnp.ones(len(y)) / len(y), x=x, y=y, xy=(xx, yy), **additional_kwargs
+        )
         p = out.pull(b, scale_by_marginals=False)
 
         assert isinstance(out, BaseDiscreteSolverOutput)
@@ -404,5 +406,7 @@ def test_plot_errors_sink(self, x: Geom_t, y: Geom_t):
         out.plot_errors()
 
     def test_plot_errors_gw(self, x: Geom_t, y: Geom_t):
-        out = GWSolver(store_inner_errors=True)(a=jnp.ones(len(x)) / len(x), b=jnp.ones(len(y)) / len(y), x=x, y=y, alpha=1.0)
+        out = GWSolver(store_inner_errors=True)(
+            a=jnp.ones(len(x)) / len(x), b=jnp.ones(len(y)) / len(y), x=x, y=y, alpha=1.0
+        )
         out.plot_errors()