diff --git a/tests/test_pdfminer_ccitt.py b/tests/test_pdfminer_ccitt.py
index 4dbf36f..412bbae 100644
--- a/tests/test_pdfminer_ccitt.py
+++ b/tests/test_pdfminer_ccitt.py
@@ -1,6 +1,6 @@
 from nose.tools import assert_equal
 
-from pdfminer.ccitt import CCITTG4Parser
+from pdfminer.ccitt import CCITTG4Parser, CCITTFaxDecoder
 
 
 class TestCCITTG4Parser():
@@ -153,3 +153,11 @@ class TestCCITTG4Parser():
         parser._do_vertical(1)
         assert_equal(parser._get_bits(), '00000001')
         return
+
+
+class TestCCITTFaxDecoder:
+    def test_b1(self):
+        decoder = CCITTFaxDecoder(5)
+        decoder.output_line(0, b'0')
+        assert_equal(decoder.close(), b'\x80')
+        return