diff --git a/numcodecs/compat.py b/numcodecs/compat.py
index 4fdde180..3ca6bacc 100644
--- a/numcodecs/compat.py
+++ b/numcodecs/compat.py
@@ -2,6 +2,7 @@
 # flake8: noqa
 from __future__ import absolute_import, print_function, division
 import sys
+import codecs
 import array
 
 
@@ -26,11 +27,11 @@
     from functools import reduce
 
 
-def ensure_text(l, encoding='utf-8'):
-    if isinstance(l, text_type):
-        return l
-    else:  # pragma: py3 no cover
-        return text_type(l, encoding=encoding)
+def ensure_text(s, encoding='utf-8'):
+    if not isinstance(s, text_type):
+        s = ensure_contiguous_ndarray(s)
+        s = codecs.decode(s, 'ascii')
+    return s
 
 
 def ensure_ndarray(buf):
diff --git a/numcodecs/tests/test_compat.py b/numcodecs/tests/test_compat.py
index ed88f171..c39be828 100644
--- a/numcodecs/tests/test_compat.py
+++ b/numcodecs/tests/test_compat.py
@@ -8,7 +8,19 @@
 import pytest
 
 
-from numcodecs.compat import ensure_bytes, PY2, ensure_contiguous_ndarray
+from numcodecs.compat import ensure_text, ensure_bytes, PY2, ensure_contiguous_ndarray, text_type
+
+
+def test_ensure_text():
+    bufs = [
+        b'adsdasdas',
+        u'adsdasdas',
+        np.asarray(memoryview(b'adsdasdas')),
+        array.array('B', b'qwertyuiqwertyui')
+    ]
+    for buf in bufs:
+        b = ensure_text(buf)
+        assert isinstance(b, text_type)
 
 
 def test_ensure_bytes():