diff --git a/test/test_linearizer.py b/test/test_linearizer.py
index 8db737e2b8..183974ee1b 100644
--- a/test/test_linearizer.py
+++ b/test/test_linearizer.py
@@ -14,6 +14,8 @@ from tinygrad.renderer.ptx import PTXRenderer
 from tinygrad.renderer.cstyle import CUDARenderer
 MOCKGPU = getenv("MOCKGPU")
 
+from tinygrad.uop.ops import print_uops # noqa: F401 # pylint: disable=unused-import
+
 class TestLinearizer(unittest.TestCase):
   def test_arg_dedup(self):
     # NOTE: this realize exists because Tensor.numpy calls .contiguous() internally
@@ -38,6 +40,22 @@ class TestLinearizer(unittest.TestCase):
     np.testing.assert_equal(a.numpy(), ta)
     np.testing.assert_equal(b.numpy(), tb)
 
+  @unittest.skip("TODO: some backends insert more casts")
+  def test_cast_there_and_back(self):
+    tst = Tensor.ones(16, dtype=dtypes.int).contiguous().realize()
+    out = tst.neg().cast(dtypes.char).cast(dtypes.int).cast(dtypes.char) * 2
+    ast = helper_linearizer_opt(out)
+    uops = get_program(ast, opts=[]).uops
+    self.assertEqual(len([x for x in uops if x.op is Ops.CAST]), 1)
+
+  @unittest.expectedFailure
+  def test_cast_back_and_there(self):
+    tst = Tensor.ones(16, dtype=dtypes.int).contiguous().realize()
+    out = tst.neg().cast(dtypes.char).cast(dtypes.int) * 2
+    ast = helper_linearizer_opt(out)
+    uops = get_program(ast, opts=[]).uops
+    self.assertEqual(len([x for x in uops if x.op is Ops.CAST]), 0)
+
   @unittest.skipIf(isinstance(Device[Device.DEFAULT].renderer, PTXRenderer), "broken on ptx")
   def test_late_bias_load(self):
     img = Tensor.empty(1, 3, 16, 16)
@@ -491,7 +509,7 @@ def copyout_outputs(outbufs:list[Buffer]) -> list[np.ndarray]:
   return [np.frombuffer(x.as_buffer(), _to_np_dtype(x.dtype)) for x in outbufs]
 
 def reset_bufs(bufs:list[Buffer]):
-  for buf in bufs: buf.copyin(np.zeros((buf.size, ), dtype=_to_np_dtype(buf.dtype)).data) # Zero to check that all values are filled
+  for buf in bufs: buf.copyin(np.zeros((buf.size*buf.dtype.itemsize,), dtype=np.uint8).data)
 
 def _helper_linearizer_opt_ast(realized_ast:UOp, real_bufs:list[Buffer], opts=[],
                                apply_tc=False, atol=1e-4, rtol=1e-4, color_sizes=[], wanna_output=[]):