diff --git a/python/tensorstore/tests/bfloat16_test.py b/python/tensorstore/tests/bfloat16_test.py
index f15a9c156..ec253cd80 100644
--- a/python/tensorstore/tests/bfloat16_test.py
+++ b/python/tensorstore/tests/bfloat16_test.py
@@ -139,14 +139,13 @@ def test_add():
   assert math.isnan(float(bfloat16(3.5) + bfloat16(float("nan"))))
 
   # Test type promotion against Numpy scalar values.
+  # See ml_dtypes.custom_float_test.py for comprehensive tests.
   assert np.float32 == type(bfloat16(3.5) + np.float16(2.25))
   assert np.float32 == type(np.float16(3.5) + bfloat16(2.25))
   assert np.float32 == type(bfloat16(3.5) + np.float32(2.25))
   assert np.float32 == type(np.float32(3.5) + bfloat16(2.25))
   assert np.float64 == type(bfloat16(3.5) + np.float64(2.25))
   assert np.float64 == type(np.float64(3.5) + bfloat16(2.25))
-  assert np.float64 == type(bfloat16(3.5) + float(2.25))
-  assert np.float64 == type(float(3.5) + bfloat16(2.25))
   assert np.float32 == type(bfloat16(3.5) + np.array(2.25, np.float32))
   assert np.float32 == type(np.array(3.5, np.float32) + bfloat16(2.25))
 
diff --git a/python/tensorstore/tests/tensorstore_test.py b/python/tensorstore/tests/tensorstore_test.py
index 55e6454fc..3b3f55b1c 100644
--- a/python/tensorstore/tests/tensorstore_test.py
+++ b/python/tensorstore/tests/tensorstore_test.py
@@ -120,7 +120,7 @@ async def test_array():
 
 async def test_array_no_copy():
   with pytest.raises(
-      ValueError, match=r"Unable to avoid copy while creating an array\."
+      ValueError, match=r"Unable to avoid copy while creating an array"
   ):
     ts.array([1, 2, 3], copy=False)
 
@@ -157,7 +157,7 @@ async def test_array_no_write():
 
   with pytest.raises(
       ValueError,
-      match=r"Unable to avoid copy while creating an array from given array\.",
+      match=r"Unable to avoid copy while creating an array",
   ):
     ts.array(x, write=True, copy=False)