diff --git a/jedi/evaluate/compiled/__init__.py b/jedi/evaluate/compiled/__init__.py
index 062f14a8..ed3d01ae 100644
--- a/jedi/evaluate/compiled/__init__.py
+++ b/jedi/evaluate/compiled/__init__.py
@@ -15,6 +15,13 @@ from jedi.evaluate.helpers import FakeName
 from . import fake
 
 
+_sep = os.path.sep
+if os.path.altsep is not None:
+    _sep += os.path.altsep
+_path_re = re.compile('(?:\.[^{0}]+|[{0}]__init__\.py)$'.format(re.escape(_sep)))
+del _sep
+
+
 class CompiledObject(Base):
     # comply with the parser
     start_pos = 0, 0
@@ -220,21 +227,27 @@ def dotted_from_fs_path(fs_path, sys_path=None):
     compares the path with sys.path and then returns the dotted_path. If the
     path is not in the sys.path, just returns None.
     """
-    sep = os.path.sep
-    shortest = None
     if sys_path is None:
         sys_path = get_sys_path()
+
+    # prefer
+    #   - UNIX
+    #     /path/to/pythonX.Y/lib-dynload
+    #     /path/to/pythonX.Y/site-packages
+    #   - Windows
+    #     C:\path\to\DLLs
+    #     C:\path\to\Lib\site-packages
+    # over
+    #   - UNIX
+    #     /path/to/pythonX.Y
+    #   - Windows
+    #     C:\path\to\Lib
+    path = ''
     for s in sys_path:
-        if fs_path.startswith(s):
-            path = fs_path[len(s):].strip(sep)
-            path = re.sub('\.[^%s]*|%s__init__.py$' % (sep, sep), '', path)
-            dotted = path.split(sep)
-            dotted = '.'.join(dotted)
-            # At this point dotted could be both `lib-dynload.datetime` and
-            # `datetime`. The shorter one is typically the module we want.
-            if shortest is None or len(shortest) > len(dotted):
-                shortest = dotted
-    return shortest
+        if (fs_path.startswith(s) and
+            len(path) < len(s)):
+            path = s
+    return _path_re.sub('', fs_path[len(path):].lstrip(os.path.sep)).replace(os.path.sep, '.')
 
 
 def load_module(path, name):
diff --git a/jedi/evaluate/imports.py b/jedi/evaluate/imports.py
index 9bd2d10b..1d7c4937 100644
--- a/jedi/evaluate/imports.py
+++ b/jedi/evaluate/imports.py
@@ -103,7 +103,8 @@ class ImportWrapper(pr.Base):
                     names += self._get_module_names([path])
 
                     if self._is_relative_import():
-                        rel_path = self._importer.get_relative_path() + '/__init__.py'
+                        rel_path = os.path.join(self._importer.get_relative_path(),
+                                                '__init__.py')
                         if os.path.exists(rel_path):
                             m = _load_module(rel_path)
                             names += m.get_defined_names()
@@ -459,7 +460,7 @@ class _Importer(object):
         if is_package_directory or current_namespace[0]:
             # is a directory module
             if is_package_directory:
-                path += '/__init__.py'
+                path = os.path.join(path, '__init__.py')
                 with open(path, 'rb') as f:
                     source = f.read()
             else:
diff --git a/test/run.py b/test/run.py
index d912d634..12aa520e 100755
--- a/test/run.py
+++ b/test/run.py
@@ -139,7 +139,7 @@ class IntegrationTestCase(object):
 
     @property
     def module_name(self):
-        return re.sub('.*/|\.py$', '', self.path)
+        return os.path.splitext(os.path.basename(self.path))[0]
 
     @property
     def line_nr_test(self):
diff --git a/test/test_evaluate/extensions/README.rst b/test/test_evaluate/extensions/README.rst
deleted file mode 100644
index 5f0b69ff..00000000
--- a/test/test_evaluate/extensions/README.rst
+++ /dev/null
@@ -1,10 +0,0 @@
-This directory contains pre-compiled extensions modules used to test completions
-for compiled modules on Travis-CI (Ubuntu 12.04 64bit).
-
-To build the extensions modules, run::
-
-    python setup.py build_ext -i
-
-
-Then move the compiled modules to their testing package ( ./**compiledXX**, where XX is the
-python version used to run setup.py).
\ No newline at end of file
diff --git a/test/test_evaluate/extensions/compiled.pyx b/test/test_evaluate/extensions/compiled.pyx
deleted file mode 100644
index 1e7c6907..00000000
--- a/test/test_evaluate/extensions/compiled.pyx
+++ /dev/null
@@ -1,6 +0,0 @@
-cdef class Foo:
-    pass
-
-
-cdef class Bar:
-    pass
diff --git a/test/test_evaluate/extensions/compiled27/__init__.py b/test/test_evaluate/extensions/compiled27/__init__.py
deleted file mode 100644
index e69de29b..00000000
diff --git a/test/test_evaluate/extensions/compiled27/compiled.so b/test/test_evaluate/extensions/compiled27/compiled.so
deleted file mode 100755
index becbfb56..00000000
Binary files a/test/test_evaluate/extensions/compiled27/compiled.so and /dev/null differ
diff --git a/test/test_evaluate/extensions/compiled32/__init__.py b/test/test_evaluate/extensions/compiled32/__init__.py
deleted file mode 100644
index e69de29b..00000000
diff --git a/test/test_evaluate/extensions/compiled32/compiled.so b/test/test_evaluate/extensions/compiled32/compiled.so
deleted file mode 100755
index df34cfa0..00000000
Binary files a/test/test_evaluate/extensions/compiled32/compiled.so and /dev/null differ
diff --git a/test/test_evaluate/extensions/setup.py b/test/test_evaluate/extensions/setup.py
deleted file mode 100644
index a13237d2..00000000
--- a/test/test_evaluate/extensions/setup.py
+++ /dev/null
@@ -1,6 +0,0 @@
-from distutils.core import setup
-from Cython.Build import cythonize
-
-setup(
-    ext_modules=cythonize("compiled.pyx")
-)
diff --git a/test/test_evaluate/test_buildout_detection.py b/test/test_evaluate/test_buildout_detection.py
index a279c5ff..70c0da1f 100644
--- a/test/test_evaluate/test_buildout_detection.py
+++ b/test/test_evaluate/test_buildout_detection.py
@@ -1,12 +1,12 @@
 import os
-from ..helpers import cwd_at
+
 from jedi._compatibility import u
+from jedi.evaluate.sys_path import (_get_parent_dir_with_file,
+                                    _get_buildout_scripts,
+                                    _check_module)
 from jedi.parser import Parser
-from jedi.evaluate.sys_path import (
-    _get_parent_dir_with_file,
-    _get_buildout_scripts,
-    _check_module
-)
+
+from ..helpers import cwd_at
 
 
 @cwd_at('test/test_evaluate/buildout_project/src/proj_name')
@@ -14,7 +14,7 @@ def test_parent_dir_with_file():
     parent = _get_parent_dir_with_file(
         os.path.abspath(os.curdir), 'buildout.cfg')
     assert parent is not None
-    assert parent.endswith('test/test_evaluate/buildout_project')
+    assert parent.endswith(os.path.join('test', 'test_evaluate', 'buildout_project'))
 
 
 @cwd_at('test/test_evaluate/buildout_project/src/proj_name')
diff --git a/test/test_evaluate/test_extension.py b/test/test_evaluate/test_extension.py
index 2f198ea7..cf15b55c 100644
--- a/test/test_evaluate/test_extension.py
+++ b/test/test_evaluate/test_extension.py
@@ -2,41 +2,30 @@
 Test compiled module
 """
 import os
-import platform
-import sys
+
 import jedi
 
-from ..helpers import cwd_at
 
-
-@cwd_at('test/test_evaluate/extensions')
 def test_completions():
-    if platform.architecture()[0] == '64bit':
-        package_name = "compiled%s%s" % sys.version_info[:2]
-        sys.path.insert(0, os.getcwd())
-        if os.path.exists(package_name):
-            s = jedi.Script("from %s import compiled; compiled." % package_name)
-            assert len(s.completions()) >= 2
+    s = jedi.Script('import _ctypes; _ctypes.')
+    assert len(s.completions()) >= 15
 
 
-@cwd_at('test/test_evaluate/extensions')
 def test_call_signatures_extension():
-    # with a cython extension
-    if platform.architecture()[0] == '64bit':
-        package_name = "compiled%s%s" % sys.version_info[:2]
-        sys.path.insert(0, os.getcwd())
-        if os.path.exists(package_name):
-            s = jedi.Script("from %s import compiled; compiled.Foo(" %
-                            package_name)
-            defs = s.call_signatures()
-            for call_def in defs:
-                for param in call_def.params:
-                    pass
+    if os.name == 'nt':
+        func = 'LoadLibrary'
+        params = 1
+    else:
+        func = 'dlopen'
+        params = 2
+    s = jedi.Script('import _ctypes; _ctypes.%s(' % (func,))
+    sigs = s.call_signatures()
+    assert len(sigs) == 1
+    assert len(sigs[0].params) == params
 
 
 def test_call_signatures_stdlib():
-    code = "import math; math.cos("
-    s = jedi.Script(code)
-    defs = s.call_signatures()
-    for call_def in defs:
-        assert len(call_def.params) == 1
+    s = jedi.Script('import math; math.cos(')
+    sigs = s.call_signatures()
+    assert len(sigs) == 1
+    assert len(sigs[0].params) == 1
diff --git a/test/test_parser/test_token.py b/test/test_parser/test_token.py
index b9e6dbc5..0295040d 100644
--- a/test/test_parser/test_token.py
+++ b/test/test_parser/test_token.py
@@ -1,10 +1,7 @@
-from jedi import parser
 from jedi._compatibility import u
+from jedi import parser
 
-try:
-    import unittest2 as unittest
-except ImportError:  # pragma: no cover
-    import unittest
+from ..helpers import unittest
 
 
 class TokenTest(unittest.TestCase):
diff --git a/test/test_utils.py b/test/test_utils.py
index 737c00a2..84b966ed 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -1,10 +1,15 @@
-import readline
+try:
+    import readline
+except ImportError:
+    readline = False
 
 from jedi import utils
-from .helpers import TestCase, cwd_at
+
+from .helpers import unittest, cwd_at
 
 
-class TestSetupReadline(TestCase):
+@unittest.skipIf(not readline, "readline not found")
+class TestSetupReadline(unittest.TestCase):
     class NameSpace(object):
         pass