diff --git a/README.mdown b/README.mdown
index 0f8a1948..e4709362 100644
--- a/README.mdown
+++ b/README.mdown
@@ -53,11 +53,11 @@ Jedi supports many of the widely used Python features:
    I don't know what to do with them.)
  - class decorators (py3k feature, are being ignored too, until I find a use
    case, that doesn't work with Jedi)
+ - simple/usual `sys.path` modifications
 
 However, it does not yet support (and probably will in future versions, because
 they are on my todo list):
 
- - `sys.path` modifications
  - assert / isinstance
  - manipulations of instances outside the instance variables, without using
    functions
diff --git a/dynamic.py b/dynamic.py
index 502dd434..af3985c3 100644
--- a/dynamic.py
+++ b/dynamic.py
@@ -10,6 +10,7 @@ import re
 import os
 
 import parsing
+import modules
 import evaluate
 import helpers
 import settings
diff --git a/functions.py b/functions.py
index 8da0a3b7..0d5bea98 100644
--- a/functions.py
+++ b/functions.py
@@ -1,13 +1,12 @@
 import re
 import weakref
-import os
 
 import parsing
-import dynamic  # must be before evaluate, because it needs to be loaded first.
+import dynamic
+import imports
 import evaluate
 import modules
 import debug
-import imports
 import settings
 import keywords
 
diff --git a/imports.py b/imports.py
index b762fdd2..c1818889 100644
--- a/imports.py
+++ b/imports.py
@@ -115,13 +115,18 @@ class ImportPath(object):
         Get the names of all modules in the search_path. This means file names
         and not names defined in the files.
         """
+        if not search_path:
+            search_path = self.sys_path_with_modifications()
         names = []
         for module_loader, name, is_pkg in pkgutil.iter_modules(search_path):
-            inf = float('inf')
-            inf_pos = (inf, inf)
+            inf_pos = (float('inf'), float('inf'))
             names.append(parsing.Name([(name, inf_pos)], inf_pos, inf_pos))
         return names
 
+    def sys_path_with_modifications(self):
+        module = self.import_stmt.get_parent_until()
+        return modules.sys_path_with_modifications(module)
+
     def follow(self):
         """
         Returns the imported modules.
diff --git a/modules.py b/modules.py
index 694d7c4c..1453e798 100644
--- a/modules.py
+++ b/modules.py
@@ -1,11 +1,16 @@
 from __future__ import with_statement
+
+from _compatibility import exec_function
+
 import re
 import tokenize
 import sys
+import os
 
 import parsing
 import builtin
 import debug
+import evaluate
 
 
 class Module(builtin.CachedModule):
@@ -170,3 +175,64 @@ class ModuleWithCursor(Module):
             return self._line_cache[line_nr - 1]
         except IndexError:
             raise StopIteration()
+
+
+@evaluate.memoize_default([])
+def sys_path_with_modifications(module):
+    def execute_code(code):
+        c = "import os; from os.path import *; result=%s"
+        variables = {}
+        try:
+            exec_function(c % code, variables)
+        except Exception:
+            return None
+        try:
+            return os.path.abspath(variables['result'])
+        except KeyError:
+            return None
+
+    curdir = os.path.abspath(os.curdir)
+    try:
+        os.chdir(os.path.dirname(module.path))
+    except OSError:
+        pass
+    sys_path = list(builtin.module_find_path)  # copy
+    try:
+        possible_stmts = module.used_names['path']
+    except KeyError:
+        return []
+
+    for p in possible_stmts:
+        try:
+            call = p.get_assignment_calls().get_only_subelement()
+        except AttributeError:
+            continue
+        n = call.name
+        if not isinstance(n, parsing.Name) or len(n.names) != 3:
+            continue
+        if n.names[:2] != ('sys', 'path'):
+            continue
+        array_cmd = n.names[2]
+        if call.execution is None:
+            continue
+        exe = call.execution
+        if not (array_cmd == 'insert' and len(exe) == 2 \
+                or array_cmd == 'append' and len(exe) == 1):
+            continue
+
+        if array_cmd == 'insert':
+            exe_type, exe.type = exe.type, parsing.Array.NOARRAY
+            exe_pop = exe.values.pop(0)
+            res = execute_code(exe.get_code())
+            if res:
+                sys_path.insert(0, res)
+            exe.type = exe_type
+            exe.values.insert(0, exe_pop)
+        elif array_cmd == 'append':
+            res = execute_code(exe.get_code())
+            if res:
+                sys_path.append(res)
+
+    # cleanup, back to old directory
+    os.chdir(curdir)
+    return sys_path
diff --git a/parsing.py b/parsing.py
index 9b882758..90883d64 100644
--- a/parsing.py
+++ b/parsing.py
@@ -900,6 +900,17 @@ class Call(Base):
             for y in self.next.generate_call_path():
                 yield y
 
+    def get_code(self):
+        if self.type == Call.NAME:
+            s = self.name.get_code()
+        else:
+            s = repr(self.name)
+        if self.execution is not None:
+            s += '(%s)' % self.execution.get_code()
+        if self.next is not None:
+            s += self.next.get_code()
+        return s
+
     def __repr__(self):
         return "<%s: %s>" % \
                 (self.__class__.__name__, self.name)
@@ -991,6 +1002,34 @@ class Array(Call):
         else:
             return iter(self.values)
 
+    def get_code(self):
+        def to_str(el):
+            try:
+                return el.get_code()
+            except AttributeError:
+                return str(el)
+
+        map = {Array.NOARRAY: '%s',
+               Array.TUPLE:   '(%s)',
+               Array.LIST:    '[%s]',
+               Array.DICT:    '{%s}',
+               Array.SET:     '{%s}'
+              }
+        inner = []
+        for i, value in enumerate(self.values):
+            s = ''
+            try:
+                key = self.keys[i]
+            except IndexError:
+                pass
+            else:
+                for el in key[i]:
+                    s += to_str(el)
+            for el in value:
+                s += to_str(el)
+            inner.append(s)
+        return map[self.type] % ', '.join(inner)
+
     def __repr__(self):
         if self.type == self.NOARRAY:
             type = 'noarray'
diff --git a/test/completion/sys_path.py b/test/completion/sys_path.py
new file mode 100644
index 00000000..7ad63034
--- /dev/null
+++ b/test/completion/sys_path.py
@@ -0,0 +1,22 @@
+
+import sys
+import os
+from os import dirname
+
+sys.path.insert(0, '../..')
+sys.path.append(dirname(os.path.abspath('thirdparty' + os.path.sep + 'asdf')))
+
+# modifications, that should fail:
+# because of sys module
+sys.path.append(sys.path[1] + '/thirdparty')
+# syntax err
+sys.path.append('a' +* '/thirdparty')
+
+#? ['evaluate']
+import evaluate
+
+#? ['goto']
+evaluate.goto
+
+#? ['pylab_']
+import pylab_
diff --git a/test/run.py b/test/run.py
index ff7ccad5..5427311e 100755
--- a/test/run.py
+++ b/test/run.py
@@ -12,6 +12,8 @@ from _compatibility import unicode, BytesIO, reduce, literal_eval, is_py25
 import functions
 import debug
 
+sys.path.pop()  # pop again, because it might affect the completion
+
 
 def run_completion_test(correct, source, line_nr, index, line, path):
     """