diff --git a/tests/rtfobj/test_is_rtf.py b/tests/rtfobj/test_is_rtf.py
new file mode 100644
index 0000000..e931775
--- /dev/null
+++ b/tests/rtfobj/test_is_rtf.py
@@ -0,0 +1,69 @@
+""" Test rtfobj.is_rtf """
+
+from __future__ import print_function
+
+import unittest
+from os.path import join
+from os import walk
+
+from oletools.rtfobj import is_rtf, RTF_MAGIC
+
+# Directory with test data, independent of current working directory
+from tests.test_utils import DATA_BASE_DIR
+
+
+class TestIsRtf(unittest.TestCase):
+    """ Tests rtfobj.is_rtf """
+
+    def test_bytearray(self):
+        """ test that is_rtf works with bytearray """
+        self.assertTrue(is_rtf(bytearray(RTF_MAGIC + b'asdfasdfasdfasdfasdf')))
+        self.assertTrue(is_rtf(bytearray(RTF_MAGIC.upper() + b'asdfasdasdff')))
+        self.assertFalse(is_rtf(bytearray(b'asdfasdfasdfasdfasdfasdfsdfsdfa')))
+
+    def test_bytes(self):
+        """ test that is_rtf works with bytearray """
+        self.assertTrue(is_rtf(RTF_MAGIC + b'asasdffdfasdfasdfasdfasdf'), True)
+        self.assertTrue(is_rtf(RTF_MAGIC.upper() + b'asdffasdfasdasdff'), True)
+        self.assertFalse(is_rtf(b'asdfasdfasdfasdfasdfasdasdfffsdfsdfa'), True)
+
+    def test_tuple(self):
+        """ test that is_rtf works with byte tuples """
+        data = tuple(byte_char for byte_char in RTF_MAGIC + b'asdfasfadfdfsdf')
+        self.assertTrue(is_rtf(data))
+
+        data = tuple(byte_char for byte_char in RTF_MAGIC.upper() + b'asfasdf')
+        self.assertTrue(is_rtf(data))
+
+        data = tuple(byte_char for byte_char in b'asdfasfassdfsdsfeereasdfwdf')
+        self.assertFalse(is_rtf(data))
+
+    def test_iterable(self):
+        """ test that is_rtf works with byte iterables """
+        data = (byte_char for byte_char in RTF_MAGIC + b'asdfasfasasdfasdfddf')
+        self.assertTrue(is_rtf(data))
+
+        data = (byte_char for byte_char in RTF_MAGIC.upper() + b'asdfassfasdf')
+        self.assertTrue(is_rtf(data))
+
+        data = (byte_char for byte_char in b'asdfasfasasdfasdfasdfsdfdwerwedf')
+        self.assertFalse(is_rtf(data))
+
+    def test_files(self):
+        """ test on real files """
+        for base_dir, _, files in walk(DATA_BASE_DIR):
+            for filename in files:
+                full_path = join(base_dir, filename)
+                expect = filename.endswith('.rtf')
+                self.assertEqual(is_rtf(full_path), expect,
+                                 'is_rtf({0}) did not return {1}'
+                                 .format(full_path, expect))
+                with open(full_path, 'rb') as handle:
+                    self.assertEqual(is_rtf(handle), expect,
+                                    'is_rtf(open({0})) did not return {1}'
+                                    .format(full_path, expect))
+
+
+# just in case somebody calls this file as a script
+if __name__ == '__main__':
+    unittest.main()