diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index bdc503a2..f74658f3 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -3,11 +3,19 @@
 Changelog
 ---------
 
-0.13.0 ()
+0.13.1 (2018-10-02)
 +++++++++++++++++++
 
+- Bugfixes, because tensorflow completions were still slow.
+
+0.13.0 (2018-10-02)
++++++++++++++++++++
+
+- A small release. Some bug fixes.
 - Remove Python 3.3 support. Python 3.3 support has been dropped by the Python
   foundation.
+- Default environments are now using the same Python version as the Python
+  process. In 0.12.x, we used to load the latest Python version on the system.
 - Added ``include_builtins`` as a parameter to usages.
 - ``goto_assignments`` has a new ``follow_builtin_imports`` parameter that
   changes the previous behavior slightly.
diff --git a/jedi/__init__.py b/jedi/__init__.py
index 84ec1782..a90f106b 100644
--- a/jedi/__init__.py
+++ b/jedi/__init__.py
@@ -36,7 +36,7 @@ As you see Jedi is pretty simple and allows you to concentrate on writing a
 good text editor, while still having very good IDE features for Python.
 """
 
-__version__ = '0.12.1'
+__version__ = '0.13.1'
 
 from jedi.api import Script, Interpreter, set_debug_function, \
     preload_module, names
diff --git a/jedi/api/__init__.py b/jedi/api/__init__.py
index 26f388e5..06721810 100644
--- a/jedi/api/__init__.py
+++ b/jedi/api/__init__.py
@@ -179,6 +179,24 @@ class Script(object):
             self._pos, self.call_signatures
         )
         completions = completion.completions()
+
+        def iter_import_completions():
+            for c in completions:
+                tree_name = c._name.tree_name
+                if tree_name is None:
+                    continue
+                definition = tree_name.get_definition()
+                if definition is not None \
+                        and definition.type in ('import_name', 'import_from'):
+                    yield c
+
+        if len(list(iter_import_completions())) > 10:
+            # For now disable completions if there's a lot of imports that
+            # might potentially be resolved. This is the case for tensorflow
+            # and has been fixed for it. This is obviously temporary until we
+            # have a better solution.
+            self._evaluator.infer_enabled = False
+
         debug.speed('completions end')
         return completions
 
diff --git a/jedi/api/environment.py b/jedi/api/environment.py
index 38c546b9..2bf6f68a 100644
--- a/jedi/api/environment.py
+++ b/jedi/api/environment.py
@@ -184,16 +184,21 @@ def get_default_environment():
     if virtual_env is not None:
         return virtual_env
 
-    for environment in find_system_environments():
-        return environment
-
-    # If no Python Environment is found, use the environment we're already
+    # If no VirtualEnv is found, use the environment we're already
     # using.
     return SameEnvironment()
 
 
-@time_cache(seconds=10 * 60)  # 10 Minutes
 def get_cached_default_environment():
+    environment = _get_cached_default_environment()
+    if environment.path != os.environ.get('VIRTUAL_ENV'):
+        _get_cached_default_environment.clear_cache()
+        return _get_cached_default_environment()
+    return environment
+
+
+@time_cache(seconds=10 * 60)  # 10 Minutes
+def _get_cached_default_environment():
     return get_default_environment()
 
 
diff --git a/jedi/api/helpers.py b/jedi/api/helpers.py
index 9e421dde..2f7af1b1 100644
--- a/jedi/api/helpers.py
+++ b/jedi/api/helpers.py
@@ -105,14 +105,17 @@ def get_stack_at_position(grammar, code_lines, module_node, pos):
         # TODO This is for now not an official parso API that exists purely
         #   for Jedi.
         tokens = grammar._tokenize(code)
-        for token_ in tokens:
-            if token_.string == safeword:
+        for token in tokens:
+            if token.string == safeword:
                 raise EndMarkerReached()
-            elif token_.prefix.endswith(safeword):
+            elif token.prefix.endswith(safeword):
                 # This happens with comments.
                 raise EndMarkerReached()
+            elif token.string.endswith(safeword):
+                yield token  # Probably an f-string literal that was not finished.
+                raise EndMarkerReached()
             else:
-                yield token_
+                yield token
 
     # The code might be indedented, just remove it.
     code = dedent(_get_code_for_stack(code_lines, module_node, pos))
diff --git a/jedi/api/replstartup.py b/jedi/api/replstartup.py
index 4c44a626..3ac84708 100644
--- a/jedi/api/replstartup.py
+++ b/jedi/api/replstartup.py
@@ -1,6 +1,8 @@
 """
 To use Jedi completion in Python interpreter, add the following in your shell
-setup (e.g., ``.bashrc``)::
+setup (e.g., ``.bashrc``). This works only on Linux/Mac, because readline is
+not available on Windows. If you still want Jedi autocompletion in your REPL,
+just use IPython instead::
 
     export PYTHONSTARTUP="$(python -m jedi repl)"
 
diff --git a/jedi/cache.py b/jedi/cache.py
index 6c0c2a83..93e2bd7f 100644
--- a/jedi/cache.py
+++ b/jedi/cache.py
@@ -126,6 +126,7 @@ def time_cache(seconds):
 
         wrapper.clear_cache = lambda: cache.clear()
         return wrapper
+
     return decorator
 
 
diff --git a/jedi/evaluate/__init__.py b/jedi/evaluate/__init__.py
index 827fbddf..ccd65cae 100644
--- a/jedi/evaluate/__init__.py
+++ b/jedi/evaluate/__init__.py
@@ -118,6 +118,9 @@ class Evaluator(object):
         self.is_analysis = False
         self.project = project
         self.access_cache = {}
+        # This setting is only temporary to limit the work we have to do with
+        # tensorflow and others.
+        self.infer_enabled = True
 
         self.reset_recursion_limitations()
         self.allow_different_encoding = True
@@ -170,6 +173,9 @@ class Evaluator(object):
         return self.project._get_sys_path(self, environment=self.environment)
 
     def eval_element(self, context, element):
+        if not self.infer_enabled:
+            return NO_CONTEXTS
+
         if isinstance(context, CompForContext):
             return eval_node(context, element)
 
diff --git a/jedi/evaluate/compiled/__init__.py b/jedi/evaluate/compiled/__init__.py
index 42c7ed76..a4904c40 100644
--- a/jedi/evaluate/compiled/__init__.py
+++ b/jedi/evaluate/compiled/__init__.py
@@ -54,8 +54,12 @@ def get_string_context_set(evaluator):
     return execute_evaluated(builtin_from_name(evaluator, u'str'))
 
 
-def load_module(evaluator, **kwargs):
-    access_path = evaluator.compiled_subprocess.load_module(**kwargs)
+def load_module(evaluator, dotted_name, **kwargs):
+    # Temporary, some tensorflow builtins cannot be loaded, so it's tried again
+    # and again and it's really slow.
+    if dotted_name.startswith('tensorflow.'):
+        return None
+    access_path = evaluator.compiled_subprocess.load_module(dotted_name=dotted_name, **kwargs)
     if access_path is None:
         return None
     return create_from_access_path(evaluator, access_path)
diff --git a/jedi/evaluate/imports.py b/jedi/evaluate/imports.py
index 25dac530..245f7edc 100644
--- a/jedi/evaluate/imports.py
+++ b/jedi/evaluate/imports.py
@@ -276,7 +276,7 @@ class Importer(object):
         return sys_path_mod
 
     def follow(self):
-        if not self.import_path:
+        if not self.import_path or not self._evaluator.infer_enabled:
             return NO_CONTEXTS
 
         import_names = tuple(
diff --git a/test/completion/basic.py b/test/completion/basic.py
index 0cb12e92..b72cc3d6 100644
--- a/test/completion/basic.py
+++ b/test/completion/basic.py
@@ -154,6 +154,9 @@ def global_define():
 #? int()
 global_var_in_func
 
+#? ['global_var_in_func']
+global_var_in_f
+
 
 def funct1():
     # From issue #610
@@ -175,6 +178,7 @@ def init_global_var_predefined():
 #? int() None
 global_var_predefined
 
+
 # -----------------
 # within docstrs
 # -----------------
diff --git a/test/completion/fstring.py b/test/completion/fstring.py
index 818ee27f..97cc1cc0 100644
--- a/test/completion/fstring.py
+++ b/test/completion/fstring.py
@@ -28,3 +28,7 @@ Fr'''sasdf''' + ''
 
 #? ['upper']
 f'xyz'.uppe
+
+
+#? 3 []
+f'f'
diff --git a/test/test_api/test_environment.py b/test/test_api/test_environment.py
index 98230e57..6e2cf36b 100644
--- a/test/test_api/test_environment.py
+++ b/test/test_api/test_environment.py
@@ -7,7 +7,7 @@ import jedi
 from jedi._compatibility import py_version
 from jedi.api.environment import get_default_environment, find_virtualenvs, \
     InvalidPythonEnvironment, find_system_environments, \
-    get_system_environment, create_environment
+    get_system_environment, create_environment, get_cached_default_environment
 
 
 def test_sys_path():
@@ -129,3 +129,10 @@ def test_get_default_environment_from_env_does_not_use_safe(tmpdir, monkeypatch)
     monkeypatch.setenv('VIRTUAL_ENV', fake_python)
     env = get_default_environment()
     assert env.path == 'fake'
+
+
+def test_changing_venv(venv_path, monkeypatch):
+    monkeypatch.setitem(os.environ, 'VIRTUAL_ENV', venv_path)
+    get_cached_default_environment()
+    monkeypatch.setitem(os.environ, 'VIRTUAL_ENV', sys.executable)
+    assert get_cached_default_environment().executable == sys.executable