diff --git a/ffcx/codegeneration/symbols.py b/ffcx/codegeneration/symbols.py
index 61af435bf..2c889947c 100644
--- a/ffcx/codegeneration/symbols.py
+++ b/ffcx/codegeneration/symbols.py
@@ -135,7 +135,9 @@ def x_component(self, mt):
 
     def J_component(self, mt):
         """Jacobian component."""
-        return L.Symbol(format_mt_name(f"J{mt.expr.ufl_domain().ufl_id()}", mt), dtype=L.DataType.REAL)
+        return L.Symbol(
+            format_mt_name(f"J{mt.expr.ufl_domain().ufl_id()}", mt), dtype=L.DataType.REAL
+        )
 
     def domain_dof_access(self, dof, component, gdim, num_scalar_dofs, restriction):
         """Domain DOF access."""