diff --git a/gpu4pyscf/df/tests/test_df_geomopt.py b/gpu4pyscf/df/tests/test_df_geomopt.py
index a25267c5..4bb7ae1e 100644
--- a/gpu4pyscf/df/tests/test_df_geomopt.py
+++ b/gpu4pyscf/df/tests/test_df_geomopt.py
@@ -82,7 +82,8 @@ def test_df_rhf_geomopt(self):
         assert np.linalg.norm(coords - coords_qchem) < 1e-4
 
     def test_df_uks_geomopt(self):
-        mf = uks.UKS(mol, xc=xc, disp=disp).density_fit()
+        mf = uks.UKS(mol, xc=xc).density_fit()
+        mf.disp = disp
         mf.grids.level = grids_level
         mf.kernel()
         mol_eq = optimize(mf, maxsteps=20)
diff --git a/gpu4pyscf/dft/roks.py b/gpu4pyscf/dft/roks.py
index 58843d78..aeed01ad 100644
--- a/gpu4pyscf/dft/roks.py
+++ b/gpu4pyscf/dft/roks.py
@@ -24,7 +24,6 @@
 from gpu4pyscf.lib import utils
 
 class ROKS(rks.KohnShamDFT, ROHF):
-    from gpu4pyscf.lib.utils import to_cpu, to_gpu, device
 
     def __init__(self, mol, xc='LDA,VWN'):
         ROHF.__init__(self, mol)
diff --git a/gpu4pyscf/grad/tests/test_geomopt.py b/gpu4pyscf/grad/tests/test_geomopt.py
index a8506d14..ef4520d9 100644
--- a/gpu4pyscf/grad/tests/test_geomopt.py
+++ b/gpu4pyscf/grad/tests/test_geomopt.py
@@ -81,7 +81,8 @@ def test_rhf_geomopt(self):
         assert np.linalg.norm(coords - coords_qchem) < 1e-4
 
     def test_uks_geomopt(self):
-        mf = uks.UKS(mol, xc=xc, disp=disp)
+        mf = uks.UKS(mol, xc=xc)
+        mf.disp = disp
         mf.grids.level = grids_level
         mf.kernel()
         mol_eq = optimize(mf, maxsteps=20)
diff --git a/gpu4pyscf/tdscf/tests/test_tdrhf.py b/gpu4pyscf/tdscf/tests/test_tdrhf.py
index 4d17f1c6..3817051f 100644
--- a/gpu4pyscf/tdscf/tests/test_tdrhf.py
+++ b/gpu4pyscf/tdscf/tests/test_tdrhf.py
@@ -33,7 +33,7 @@ def setUpClass(cls):
         mol.basis = '631g'
         mol.symmetry = True
         cls.mol = mol.build()
-        cls.mf = mf = scf.RHF(mol).to_gpu().run()
+        cls.mf = scf.RHF(mol).to_gpu().run()
         cls.df_mf = scf.RHF(mol).to_gpu().density_fit().run()
         cls.nstates = 5 # make sure first 3 states are converged