diff --git a/jedi/_compatibility.py b/jedi/_compatibility.py
index 11bd1f89..d7015268 100644
--- a/jedi/_compatibility.py
+++ b/jedi/_compatibility.py
@@ -60,6 +60,15 @@ try:
 except NameError:
     unicode = str
 
+if is_py3k:
+    utf8 = lambda s: s
+else:
+    utf8 = lambda s: s.decode('utf-8')
+
+utf8.__doc__ = """
+Decode a raw string into unicode object.  Do nothing in Python 3.
+"""
+
 # exec function
 if is_py3k:
     def exec_function(source, global_map):
diff --git a/jedi/api.py b/jedi/api.py
index 751026bd..a765fbc6 100644
--- a/jedi/api.py
+++ b/jedi/api.py
@@ -60,9 +60,17 @@ class Script(object):
     :type col: int
     :param source_path: The path in the os, the current module is in.
     :type source_path: string or None
+    :param source_encoding: encoding for decoding `source`, when it
+                            is not a `unicode` object.
+    :type source_encoding: string
     """
-    def __init__(self, source, line, column, source_path):
-        source = unicode(source)
+    def __init__(self, source, line, column, source_path,
+                 source_encoding='utf-8'):
+        try:
+            source = unicode(source, source_encoding, 'replace')
+            # Use 'replace' over 'ignore' to hold code structure.
+        except TypeError:  # `source` is already a unicode object
+            pass
         self.pos = line, column
         self.module = modules.ModuleWithCursor(source_path, source=source,
                                                             position=self.pos)
diff --git a/test/regression.py b/test/regression.py
index 498762a7..792f87f9 100755
--- a/test/regression.py
+++ b/test/regression.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+# -*- coding: utf-8 -*-
 import os
 import sys
 import unittest
@@ -10,7 +11,7 @@ sys.path.append(abspath(dirname(abspath(__file__)) + '/../jedi'))
 os.chdir(os.path.dirname(os.path.abspath(__file__)) + '/../jedi')
 sys.path.append('.')
 
-from _compatibility import is_py25
+from _compatibility import is_py25, utf8
 import api
 
 #api.set_debug_function(api.debug.print_to_stdout)
@@ -211,6 +212,17 @@ class TestRegression(Base):
         else:
             assert len(self.complete(s))
 
+    def test_multibyte_script(self):
+        """ `jedi.Script` must accept multi-byte string source. """
+        try:
+            code = unicode("import datetime; datetime.d")
+            comment = utf8("# multi-byte comment あいうえお")
+            s = (unicode('%s\n%s') % (code, comment)).encode('utf-8')
+        except NameError:
+            pass # python 3 has no unicode method
+        else:
+            assert len(self.complete(s, (1, len(code))))
+
     def test_os_nowait(self):
         """ github issue #45 """
         s = self.complete("import os; os.P_")