diff --git a/test/test_function_barcode.py b/test/test_function_barcode.py
index 4205eba..c6ec958 100644
--- a/test/test_function_barcode.py
+++ b/test/test_function_barcode.py
@@ -31,4 +31,4 @@ def test_lacks_support(bctype, supports_b):
     with pytest.raises(BarcodeTypeError):
         instance.barcode('test', bctype)
 
-    assert instance.output == ''
\ No newline at end of file
+    assert instance.output == b''
\ No newline at end of file
diff --git a/test/test_function_text.py b/test/test_function_text.py
index dc25842..7f91c95 100644
--- a/test/test_function_text.py
+++ b/test/test_function_text.py
@@ -19,7 +19,7 @@ def test_function_text_dies_ist_ein_test_lf():
     """test the text printing function with simple string and compare output"""
     instance = Dummy()
     instance.text('Dies ist ein Test.\n')
-    assert instance.output == 'Dies ist ein Test.\n'
+    assert instance.output == b'Dies ist ein Test.\n'
 
 
 def test_block_text():
@@ -27,4 +27,4 @@ def test_block_text():
     printer.block_text(
         "All the presidents men were eating falafel for breakfast.", font='a')
     assert printer.output == \
-        'All the presidents men were eating falafel\nfor breakfast.'
+        b'All the presidents men were eating falafel\nfor breakfast.'