diff --git a/test/test_grudge.py b/test/test_grudge.py
index 4d260e780bdcf9e6f02b986eafe24f0aa293d1d8..1b375bdfe7241422142b4d8511235738b214253c 100644
--- a/test/test_grudge.py
+++ b/test/test_grudge.py
@@ -1139,6 +1139,89 @@ def test_empty_boundary(actx_factory):
         assert len(component) == len(discr.discr_from_dd(BTAG_NONE).groups)
 
 
+def test_operator_compiler_overwrite(actx_factory):
+    """Tests that the same expression in ``eval_code`` and ``discr_code``
+    does not confuse the OperatorCompiler in grudge/symbolic/compiler.py.
+    """
+
+    actx = actx_factory()
+
+    ambient_dim = 2
+    target_order = 4
+
+    from meshmode.mesh.generation import generate_regular_rect_mesh
+    mesh = generate_regular_rect_mesh(
+            a=(-0.5,)*ambient_dim, b=(0.5,)*ambient_dim,
+            n=(8,)*ambient_dim, order=1)
+    discr = DiscretizationCollection(actx, mesh, order=target_order)
+
+    # {{{ test
+
+    sym_u = sym.nodes(ambient_dim)
+    sym_div_u = sum(d(u) for d, u in zip(sym.nabla(ambient_dim), sym_u))
+
+    div_u = bind(discr, sym_div_u)(actx)
+    error = bind(discr, sym.norm(2, sym.var("x")))(actx, x=div_u - discr.dim)
+    logger.info("error: %.5e", error)
+
+    # }}}
+
+
+@pytest.mark.parametrize("ambient_dim", [
+    2,
+    # FIXME, cf. https://github.com/inducer/grudge/pull/78/
+    pytest.param(3, marks=pytest.mark.xfail)
+    ])
+def test_incorrect_assignment_aggregation(actx_factory, ambient_dim):
+    """Tests that the greedy assignemnt aggregation code works on a non-trivial
+    expression (on which it didn't work at the time of writing).
+    """
+
+    actx = actx_factory()
+
+    target_order = 4
+
+    from meshmode.mesh.generation import generate_regular_rect_mesh
+    mesh = generate_regular_rect_mesh(
+            a=(-0.5,)*ambient_dim, b=(0.5,)*ambient_dim,
+            n=(8,)*ambient_dim, order=1)
+    discr = DiscretizationCollection(actx, mesh, order=target_order)
+
+    # {{{ test with a relative norm
+
+    from grudge.dof_desc import DD_VOLUME
+    dd = DD_VOLUME
+    sym_x = sym.make_sym_array("y", ambient_dim, dd=dd)
+    sym_y = sym.make_sym_array("y", ambient_dim, dd=dd)
+
+    sym_norm_y = sym.norm(2, sym_y, dd=dd)
+    sym_norm_d = sym.norm(2, sym_x - sym_y, dd=dd)
+    sym_op = sym_norm_d / sym_norm_y
+    logger.info("%s", sym.pretty(sym_op))
+
+    # FIXME: this shouldn't raise a RuntimeError
+    with pytest.raises(RuntimeError):
+        bind(discr, sym_op)(actx, x=1.0, y=discr.discr_from_dd(dd).nodes())
+
+    # }}}
+
+    # {{{ test with repeated mass inverses
+
+    sym_minv_y = sym.cse(sym.InverseMassOperator()(sym_y), "minv_y")
+
+    sym_u = make_obj_array([0.5 * sym.Ones(dd), 0.0, 0.0])[:ambient_dim]
+    sym_div_u = sum(d(u) for d, u in zip(sym.nabla(ambient_dim), sym_u))
+
+    sym_op = sym.MassOperator(dd)(sym_u) \
+            + sym.MassOperator(dd)(sym_minv_y * sym_div_u)
+    logger.info("%s", sym.pretty(sym_op))
+
+    # FIXME: this shouldn't raise a RuntimeError either
+    bind(discr, sym_op)(actx, y=discr.discr_from_dd(dd).nodes())
+
+    # }}}
+
+
 # You can test individual routines by typing
 # $ python test_grudge.py 'test_routine()'