diff --git a/tests/firedrake/output/test_adjoint_disk_checkpointing.py b/tests/firedrake/output/test_adjoint_disk_checkpointing.py
index 2f4b15e9f7..c1cf3daaa0 100644
--- a/tests/firedrake/output/test_adjoint_disk_checkpointing.py
+++ b/tests/firedrake/output/test_adjoint_disk_checkpointing.py
@@ -104,6 +104,6 @@ def test_disk_checkpointing_successive_writes():
 
     J = assemble(v*dx)
     Jhat = ReducedFunctional(J, Control(u))
-    assert np.allclose(J, Jhat(1))
+    assert np.allclose(J, Jhat(Function(cg_space).interpolate(1.)))
     pause_disk_checkpointing()
     tape.clear_tape()
diff --git a/tests/firedrake/regression/test_adjoint_operators.py b/tests/firedrake/regression/test_adjoint_operators.py
index a8f5149657..8d4c0ab796 100644
--- a/tests/firedrake/regression/test_adjoint_operators.py
+++ b/tests/firedrake/regression/test_adjoint_operators.py
@@ -717,7 +717,7 @@ def test_init_constant():
     c2.assign(c1)
     J = assemble(c2*dx(domain=mesh))
     rf = ReducedFunctional(J, Control(c1))
-    assert np.isclose(rf(-1.0), -1.0)
+    assert np.isclose(rf(Function(R, val=-1.0)), -1.0)
 
 
 @pytest.mark.skipcomplex  # Taping for complex-valued 0-forms not yet done