diff --git a/jedi/api/file_name.py b/jedi/api/file_name.py
index e41fef07..b0486c67 100644
--- a/jedi/api/file_name.py
+++ b/jedi/api/file_name.py
@@ -93,7 +93,7 @@ def _add_strings(context, nodes, add_slash=False):
             return None
         if not first and add_slash:
             string += os.path.sep
-        string += str(s, errors='replace')
+        string += s
         first = False
     return string
 
diff --git a/jedi/inference/helpers.py b/jedi/inference/helpers.py
index 3e4d3952..8f7052d6 100644
--- a/jedi/inference/helpers.py
+++ b/jedi/inference/helpers.py
@@ -144,7 +144,7 @@ def get_int_or_none(value):
 
 
 def get_str_or_none(value):
-    return _get_safe_value_or_none(value, (bytes, unicode))
+    return _get_safe_value_or_none(value, str)
 
 
 def is_number(value):
diff --git a/test/test_api/test_completion.py b/test/test_api/test_completion.py
index a0d23ef3..45716708 100644
--- a/test/test_api/test_completion.py
+++ b/test/test_api/test_completion.py
@@ -244,9 +244,7 @@ current_dirname = os.path.basename(dirname(dirname(dirname(__file__))))
         ('example.py', 'x = f("te" + "st"', 16, [s]),
         ('example.py', 'x = f("te" + "st")', 16, [s]),
         ('example.py', 'x = f("t" + "est")', 16, [s]),
-        # This is actually not correct, but for now leave it here, because of
-        # Python 2.
-        ('example.py', 'x = f(b"t" + "est")', 17, [s]),
+        ('example.py', 'x = f(b"t" + "est")', 17, []),
         ('example.py', '"test" + "', None, [s]),
 
         # __file__