diff --git a/.travis.yml b/.travis.yml
index 876af276..188c99f0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,7 @@ env:
     - TOXENV=py32
     - TOXENV=py33
     - TOXENV=py34
+    - TOXENV=py35
     - TOXENV=pypy
     - TOXENV=cov
     - TOXENV=sith
@@ -14,8 +15,9 @@ matrix:
         - env: TOXENV=cov
         - env: TOXENV=sith
         - env: TOXENV=pypy
+python: 3.5
 install:
-    - pip install --quiet --use-mirrors tox
+    - pip install --quiet tox 'virtualenv<14.0.0' 'pip<8.0.0'
 script:
     - tox
 after_script:
@@ -23,3 +25,4 @@ after_script:
       pip install --quiet --use-mirrors coveralls;
       coveralls;
       fi
+
diff --git a/AUTHORS.txt b/AUTHORS.txt
index 076e8cc9..9e7f9800 100644
--- a/AUTHORS.txt
+++ b/AUTHORS.txt
@@ -37,5 +37,6 @@ Kevin Kelley (@kelleyk) <kelleyk@kelleyk.net>
 Sid Shanker (@squidarth) <sid.p.shanker@gmail.com>
 Reinoud Elhorst (@reinhrst)
 Guido van Rossum (@gvanrossum) <guido@python.org>
+Dmytro Sadovnychyi (@sadovnychyi) <jedi@dmit.ro>
 
 Note: (@user) means a github user name.
diff --git a/jedi/api/__init__.py b/jedi/api/__init__.py
index e057c5f1..02dd735c 100644
--- a/jedi/api/__init__.py
+++ b/jedi/api/__init__.py
@@ -3,6 +3,9 @@ The API basically only provides one class. You can create a :class:`Script` and
 use its methods.
 
 Additionally you can add a debug function with :func:`set_debug_function`.
+Alternatively, if you don't need a custom function and are happy with printing
+debug messages to stdout, simply call :func:`set_debug_function` without
+arguments.
 
 .. warning:: Please, note that Jedi is **not thread safe**.
 """
@@ -529,6 +532,8 @@ def set_debug_function(func_cb=debug.print_to_stdout, warnings=True,
     """
     Define a callback debug function to get all the debug messages.
 
+    If you don't specify any arguments, debug messages will be printed to stdout.
+
     :param func_cb: The callback function for debug messages, with n params.
     """
     debug.debug_function = func_cb
diff --git a/jedi/common.py b/jedi/common.py
index fc3151af..3655c0bd 100644
--- a/jedi/common.py
+++ b/jedi/common.py
@@ -135,7 +135,7 @@ def source_to_unicode(source, encoding=None):
             return possible_encoding.group(1)
         else:
             # the default if nothing else has been set -> PEP 263
-            return encoding if encoding is not None else 'iso-8859-1'
+            return encoding if encoding is not None else 'utf-8'
 
     if isinstance(source, unicode):
         # only cast str/bytes
diff --git a/tox.ini b/tox.ini
index 526092fc..4211ff44 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py26, py27, py32, py33, py34
+envlist = py26, py27, py32, py33, py34, py35
 [testenv]
 deps =
     pytest>=2.3.5
@@ -18,6 +18,11 @@ commands =
 deps =
     unittest2
     {[testenv]deps}
+[testenv:py32]
+deps =
+    pip<8.0.0
+    virtualenv<14.0.0
+    {[testenv]deps}
 [testenv:cov]
 deps =
     coverage