diff --git a/nilmdb/client/client.py b/nilmdb/client/client.py
index 31ccf66..c82e000 100644
--- a/nilmdb/client/client.py
+++ b/nilmdb/client/client.py
@@ -159,7 +159,7 @@ class Client(object):
         so it will be broken into reasonably-sized chunks and
         start/end will be deduced if missing."""
         with self.stream_insert_context(path, start, end) as ctx:
-            if isinstance(data, str):
+            if isinstance(data, bytes):
                 ctx.insert(data)
             else:
                 for chunk in data:
diff --git a/tests/test_client.py b/tests/test_client.py
index 22813e5..4e11dc7 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -291,22 +291,32 @@ class TestClient(object):
                          ">= end time 1332511201000000", str(e.exception))
                is not None)
 
+        def check_data():
+            # Verify the intervals.  Should be just one, even if the data
+            # was inserted in chunks, due to nilmdb interval concatenation.
+            intervals = list(client.stream_intervals("/newton/prep"))
+            eq_(intervals, [[start, start + 119999777]])
+
+            # Try some overlapping data -- just insert it again
+            data = timestamper.TimestamperRate(testfile, start, 120)
+            with assert_raises(ClientError) as e:
+                result = client.stream_insert("/newton/prep", data)
+            in_("400 Bad Request", str(e.exception))
+            in_("verlap", str(e.exception))
+
         # Now do the real load
         data = timestamper.TimestamperRate(testfile, start, 120)
         result = client.stream_insert("/newton/prep", data,
                                       start, start + 119999777)
+        check_data()
 
-        # Verify the intervals.  Should be just one, even if the data
-        # was inserted in chunks, due to nilmdb interval concatenation.
-        intervals = list(client.stream_intervals("/newton/prep"))
-        eq_(intervals, [[start, start + 119999777]])
-
-        # Try some overlapping data -- just insert it again
+        # Try inserting directly-passed data
+        client.stream_remove("/newton/prep", start, start + 119999777)
         data = timestamper.TimestamperRate(testfile, start, 120)
-        with assert_raises(ClientError) as e:
-            result = client.stream_insert("/newton/prep", data)
-        in_("400 Bad Request", str(e.exception))
-        in_("verlap", str(e.exception))
+        data_bytes = b''.join(data)
+        result = client.stream_insert("/newton/prep", data_bytes,
+                                      start, start + 119999777)
+        check_data()
 
         nilmdb.client.client.StreamInserter._max_data = old_max_data
         client.close()