diff --git a/jedi/api/__init__.py b/jedi/api/__init__.py
index 40102047..01ed0a34 100644
--- a/jedi/api/__init__.py
+++ b/jedi/api/__init__.py
@@ -570,6 +570,13 @@ class Interpreter(Script):
         super(Interpreter, self).__init__(source, **kwds)
         self.namespaces = namespaces
 
+        # Don't use the fast parser, because it does crazy stuff that we don't
+        # need in our very simple and small code here (that is always
+        # changing).
+        self._parser = UserContextParser(self._grammar, self.source,
+                                         self._orig_path, self._pos,
+                                         self._user_context,
+                                         use_fast_parser=False)
         interpreter.add_namespaces_to_parser(self._evaluator, namespaces,
                                              self._parser.module())
 
diff --git a/jedi/parser/tree.py b/jedi/parser/tree.py
index fdb24aec..b68fa071 100644
--- a/jedi/parser/tree.py
+++ b/jedi/parser/tree.py
@@ -18,7 +18,7 @@ The easiest way to play with this module is to use :class:`parsing.Parser`.
 >>> parser = Parser(load_grammar(), u('import os'), 'example.py')
 >>> submodule = parser.module
 >>> submodule
-<SubModule: example.py@1-2>
+<SubModule: example.py@1-1>
 
 Any subclasses of :class:`Scope`, including :class:`SubModule` has an attribute
 :attr:`imports <Scope.imports>`:
diff --git a/jedi/parser/user_context.py b/jedi/parser/user_context.py
index 8e4f5da1..e1ff1f5b 100644
--- a/jedi/parser/user_context.py
+++ b/jedi/parser/user_context.py
@@ -4,7 +4,7 @@ import keyword
 
 from jedi import cache
 from jedi import common
-from jedi.parser import tokenize
+from jedi.parser import tokenize, Parser
 from jedi._compatibility import u
 from jedi.parser.fast import FastParser
 from jedi.parser import tree as pr
@@ -235,19 +235,24 @@ class UserContext(object):
 
 
 class UserContextParser(object):
-    def __init__(self, grammar, source, path, position, user_context):
+    def __init__(self, grammar, source, path, position, user_context,
+                 use_fast_parser=True):
         self._grammar = grammar
         self._source = source
         self._path = path and os.path.abspath(path)
         self._position = position
         self._user_context = user_context
+        self._use_fast_parser = use_fast_parser
 
     @cache.underscore_memoization
     def _parser(self):
         cache.invalidate_star_import_cache(self._path)
-        parser = FastParser(self._grammar, self._source, self._path)
-        # Don't pickle that module, because the main module is changing quickly
-        cache.save_parser(self._path, None, parser, pickling=False)
+        if self._use_fast_parser:
+            parser = FastParser(self._grammar, self._source, self._path)
+            # Don't pickle that module, because the main module is changing quickly
+            cache.save_parser(self._path, None, parser, pickling=False)
+        else:
+            parser = Parser(self._grammar, self._source, self._path)
         return parser
 
     @cache.underscore_memoization