diff --git a/jedi/fast_parser.py b/jedi/fast_parser.py
index 05ed3e32..e748f5a4 100644
--- a/jedi/fast_parser.py
+++ b/jedi/fast_parser.py
@@ -1,8 +1,9 @@
 import re
 import operator
 
-import parsing
 from _compatibility import use_metaclass, reduce, property
+import settings
+import parsing
 
 parser_cache = {}
 
@@ -211,7 +212,9 @@ class FastParser(use_metaclass(CachedFastParser)):
             parts[0] += parts[1]
             parts.pop(1)
 
-        #self.parsers[:] = []
+        if settings.fast_parser_always_reparse:
+            self.parsers[:] = []
+
         # dict comprehensions are not available in py2.5/2.6 :-(
         hashes = dict((p.hash, p) for p in self.parsers)
 
diff --git a/jedi/settings.py b/jedi/settings.py
index 4a2c467a..789ac955 100644
--- a/jedi/settings.py
+++ b/jedi/settings.py
@@ -18,9 +18,15 @@ add_bracket_after_function = False
 # parser
 # ----------------
 
-# Use the fast parser, may cause problems sometimes.
+# Use the fast parser. This means that reparsing is only being done if
+# something has been changed e.g. to a function. If this happens, only the
+# function is being reparsed.
 fast_parser = True
 
+# This is just a debugging option. Always reparsing means that the fast parser
+# is basically useless. So don't use it.
+fast_parser_always_reparse = False
+
 # ----------------
 # dynamic stuff
 # ----------------