diff --git a/tests/test_shm.py b/tests/test_shm.py
index c183040c..2b7a382f 100644
--- a/tests/test_shm.py
+++ b/tests/test_shm.py
@@ -70,7 +70,10 @@ async def child_read_shm_list(
 ) -> None:
 
     # attach in child
-    shml = attach_shm_list(key=shm_key)
+    shml = attach_shm_list(
+        key=shm_key,
+        # dtype=str if use_str else float,
+    )
     await ctx.started(shml.key)
 
     async with ctx.open_stream() as stream:
@@ -92,7 +95,9 @@ async def child_read_shm_list(
 
 
 @pytest.mark.parametrize(
-    'use_str', [False, True],
+    'use_str',
+    [False, True],
+    ids=lambda i: f'use_str_values={i}',
 )
 @pytest.mark.parametrize(
     'frame_size',
@@ -106,7 +111,7 @@ def test_parent_writer_child_reader(
 
     async def main():
         async with tractor.open_nursery(
-            debug_mode=True,
+            # debug_mode=True,
         ) as an:
 
             portal = await an.start_actor(
@@ -121,6 +126,7 @@ async def main():
             shml = open_shm_list(
                 key=key,
                 size=seq_size,
+                dtype=str if use_str else float,
                 readonly=False,
             )
 
@@ -143,7 +149,7 @@ async def main():
                     if use_str:
                         val = str(val)
 
-                    print(f'(parent): writing {val}')
+                    # print(f'(parent): writing {val}')
                     shml[i] = val
 
                     # only on frame fills do we
diff --git a/tractor/_shm.py b/tractor/_shm.py
index 2ce148da..c4c17335 100644
--- a/tractor/_shm.py
+++ b/tractor/_shm.py
@@ -460,7 +460,6 @@ def flush(self) -> None:
 
 
 def open_shm_ndarray(
-
     key: Optional[str] = None,
     size: int = int(2 ** 10),
     dtype: np.dtype | None = None,
@@ -799,7 +798,6 @@ def open_shm_list(
             None: None,
         }[dtype]
         sequence = [default] * size
-        # sequence = [0.] * size
 
     shml = ShmList(
         sequence=sequence,