diff --git a/distributed/protocol/numpy.py b/distributed/protocol/numpy.py
index e146df937e8..e963d557ca3 100644
--- a/distributed/protocol/numpy.py
+++ b/distributed/protocol/numpy.py
@@ -50,7 +50,7 @@ def serialize_numpy_ndarray(x):
 
     data = x.view('u1').data
 
-    if blosc and data.nbytes > 1e5:
+    if blosc and x.nbytes > 1e5:
         frames = frame_split_size([data])
         if sys.version_info.major == 2:
             frames = [ensure_bytes(frame) for frame in frames]
diff --git a/distributed/protocol/tests/test_numpy.py b/distributed/protocol/tests/test_numpy.py
index 8b976dedbb2..3f23b044111 100644
--- a/distributed/protocol/tests/test_numpy.py
+++ b/distributed/protocol/tests/test_numpy.py
@@ -138,4 +138,5 @@ def test_dont_compress_uncompressable_data():
     x = np.ones(100)
     header, [data] = serialize(x)
     assert 'compression' not in header
-    assert data.obj.ctypes.data == x.ctypes.data
+    if isinstance(data, memoryview):
+        assert data.obj.ctypes.data == x.ctypes.data