diff --git a/jedi/api/__init__.py b/jedi/api/__init__.py
index df78b88f..4d44759d 100644
--- a/jedi/api/__init__.py
+++ b/jedi/api/__init__.py
@@ -155,7 +155,7 @@ class Script(object):
         is_package = False
         if self.path is not None:
             import_names, is_p = transform_path_to_dotted(
-                self._evaluator.get_sys_path(),
+                self._evaluator.get_sys_path(add_parent_paths=False),
                 self.path
             )
             if import_names is not None:
diff --git a/jedi/api/project.py b/jedi/api/project.py
index 0e319279..f8f32917 100644
--- a/jedi/api/project.py
+++ b/jedi/api/project.py
@@ -77,7 +77,8 @@ class Project(object):
 
         py2_comp(path, **kwargs)
 
-    def _get_base_sys_path(self, environment=None):
+    @evaluator_as_method_param_cache()
+    def _get_base_sys_path(self, evaluator, environment=None):
         if self._sys_path is not None:
             return self._sys_path
 
@@ -93,7 +94,7 @@ class Project(object):
         return sys_path
 
     @evaluator_as_method_param_cache()
-    def _get_sys_path(self, evaluator, environment=None):
+    def _get_sys_path(self, evaluator, environment=None, add_parent_paths=True):
         """
         Keep this method private for all users of jedi. However internally this
         one is used like a public method.
@@ -101,19 +102,20 @@ class Project(object):
         suffixed = []
         prefixed = []
 
-        sys_path = list(self._get_base_sys_path(environment))
+        sys_path = list(self._get_base_sys_path(evaluator, environment))
         if self._smart_sys_path:
             prefixed.append(self._path)
 
             if evaluator.script_path is not None:
                 suffixed += discover_buildout_paths(evaluator, evaluator.script_path)
 
-                traversed = list(traverse_parents(evaluator.script_path))
+                if add_parent_paths:
+                    traversed = list(traverse_parents(evaluator.script_path))
 
-                # AFAIK some libraries have imports like `foo.foo.bar`, which
-                # leads to the conclusion to by default prefer longer paths
-                # rather than shorter ones by default.
-                suffixed += reversed(traversed)
+                    # AFAIK some libraries have imports like `foo.foo.bar`, which
+                    # leads to the conclusion to by default prefer longer paths
+                    # rather than shorter ones by default.
+                    suffixed += reversed(traversed)
 
         if self._django:
             prefixed.append(self._path)
diff --git a/jedi/evaluate/__init__.py b/jedi/evaluate/__init__.py
index 4fa23557..bba7923b 100644
--- a/jedi/evaluate/__init__.py
+++ b/jedi/evaluate/__init__.py
@@ -172,9 +172,9 @@ class Evaluator(object):
         self.recursion_detector = recursion.RecursionDetector()
         self.execution_recursion_detector = recursion.ExecutionRecursionDetector(self)
 
-    def get_sys_path(self):
+    def get_sys_path(self, **kwargs):
         """Convenience function"""
-        return self.project._get_sys_path(self, environment=self.environment)
+        return self.project._get_sys_path(self, environment=self.environment, **kwargs)
 
     def eval_element(self, context, element):
         if not self.infer_enabled:
diff --git a/test/test_evaluate/test_imports.py b/test/test_evaluate/test_imports.py
index 7e875e3a..6634bea2 100644
--- a/test/test_evaluate/test_imports.py
+++ b/test/test_evaluate/test_imports.py
@@ -12,7 +12,7 @@ from jedi._compatibility import find_module_py33, find_module
 from jedi.evaluate import compiled
 from jedi.evaluate import imports
 from jedi.api.project import Project
-from ..helpers import cwd_at, get_example_dir
+from ..helpers import cwd_at, get_example_dir, test_dir
 
 THIS_DIR = os.path.dirname(__file__)
 
@@ -396,3 +396,9 @@ def test_relative_import_out_of_file_system(Script):
 )
 def test_level_to_import_path(level, directory, project_path, result):
     assert imports._level_to_base_import_path(project_path, directory, level) == result
+
+
+def test_import_name_calculation(Script):
+    s = Script(path=os.path.join(test_dir, 'completion', 'isinstance.py'))
+    m = s._get_module()
+    assert m.string_names == ('test', 'completion', 'isinstance')