diff --git a/tests/firedrake/slate/test_assemble_tensors.py b/tests/firedrake/slate/test_assemble_tensors.py
index 40830118d1..42754798b6 100644
--- a/tests/firedrake/slate/test_assemble_tensors.py
+++ b/tests/firedrake/slate/test_assemble_tensors.py
@@ -306,22 +306,19 @@ def test_diagonal(mass, matrix_mixed_nofacet):
     ref = assemble(mass, diagonal=True).dat.data
     ref = np.concatenate(ref) if len(np.shape(ref)) > 1 else ref  # vectorspace
     ref = np.concatenate(ref) if len(np.shape(ref)) > 1 else ref  # tensorspace
-    for r, d in zip(ref, np.diag(res)):
-        assert np.allclose(r, d, rtol=1e-14)
+    assert np.allclose(ref, np.diag(res), rtol=1e-14)
 
     # test matrix built from diagonal for non mass matrix
     res2 = assemble(DiagonalTensor(Tensor(matrix_mixed_nofacet))).M.values
     ref2 = np.concatenate(assemble(matrix_mixed_nofacet, diagonal=True).dat.data)
-    for r, d in zip(res2, np.diag(ref2)):
-        assert np.allclose(r, d, rtol=1e-14)
+    assert np.allclose(ref2, np.diag(res2), rtol=1e-14)
 
     # test matrix built from diagonal
     # for a Slate expression on a non mass matrix
     A = Tensor(matrix_mixed_nofacet)
     res3 = assemble(DiagonalTensor(A+A)).M.values
     ref3 = np.concatenate(assemble(matrix_mixed_nofacet+matrix_mixed_nofacet, diagonal=True).dat.data)
-    for r, d in zip(res3, np.diag(ref3)):
-        assert np.allclose(r, d, rtol=1e-14)
+    assert np.allclose(ref3, np.diag(res3), rtol=1e-14)
 
 
 @pytest.mark.parametrize("function_space", ["dg0"], indirect=True)