diff --git a/jedi/__init__.py b/jedi/__init__.py
index 31da8e79..feff0bba 100644
--- a/jedi/__init__.py
+++ b/jedi/__init__.py
@@ -42,7 +42,8 @@ import sys
 # imports and circular imports... Just avoid it:
 sys.path.insert(0, __path__[0])
 
-from .api import Script, NotFoundError, set_debug_function, _quick_complete
+from .api import Script, NotFoundError, set_debug_function, _quick_complete, \
+                 preload_module
 from . import settings
 
 sys.path.pop(0)
diff --git a/jedi/api.py b/jedi/api.py
index e4f7f532..edae10ca 100644
--- a/jedi/api.py
+++ b/jedi/api.py
@@ -522,6 +522,18 @@ def defined_names(source, source_path=None, source_encoding='utf-8'):
     return api_classes._defined_names(parser.scope)
 
 
+def preload_module(*modules):
+    """
+    Preloading modules tells Jedi to load a module now, instead of lazy parsing
+    of modules. Usful for IDEs, to control which modules to load on startup.
+
+    :param modules: different module names, list of string.
+    """
+    for m in modules:
+        s = "import %s as x; x." % m
+        Script(s, 1, len(s), None).complete()
+
+
 def set_debug_function(func_cb=debug.print_to_stdout, warnings=True,
                                             notices=True, speed=True):
     """
diff --git a/test/test_regression.py b/test/test_regression.py
index fa0c93dd..31aa058a 100755
--- a/test/test_regression.py
+++ b/test/test_regression.py
@@ -15,11 +15,9 @@ from .base import TestBase, unittest, cwd_at
 
 import jedi
 from jedi._compatibility import utf8, unicode
-from jedi import api, parsing
+from jedi import api, parsing, common
 api_classes = api.api_classes
 
-import pytest
-
 #jedi.set_debug_function(jedi.debug.print_to_stdout)
 
 
@@ -231,11 +229,9 @@ class TestRegression(TestBase):
         # jedi-vim #70
         s = """def foo("""
         assert self.function_definition(s) is None
-        jedi.set_debug_function(jedi.debug.print_to_stdout)
         # jedi-vim #116
         s = """import functools; test = getattr(functools, 'partial'); test("""
         check(self.function_definition(s), 'partial', 0)
-        jedi.set_debug_function(None)
 
     def test_function_definition_empty_paren_pre_space(self):
         s = textwrap.dedent("""\
@@ -437,6 +433,26 @@ class TestFeature(TestBase):
         any_re"""
         self.assertEqual(self.goto_definitions(s)[0].full_name, 're.RegexObject')
 
+    def test_preload_modules(self):
+        def check_loaded(*modules):
+            # + 1 for builtin, +1 for None module (currently used)
+            assert len(new) == len(modules) + 2
+            for i in modules + ('__builtin__',):
+                assert [i in k for k in new.keys() if k is not None]
+
+        from jedi import cache
+        temp_cache, cache.parser_cache = cache.parser_cache, {}
+        new = cache.parser_cache
+        with common.ignored(KeyError): # performance of tests -> no reload
+            new['__builtin__'] = temp_cache['__builtin__']
+
+        jedi.preload_module('datetime')
+        check_loaded('datetime')
+        jedi.preload_module('json', 'token')
+        check_loaded('datetime', 'json', 'token')
+
+        cache.parser_cache = temp_cache
+
     def test_quick_completion(self):
         sources = [
             ('import json; json.l', (1, 19)),