diff --git a/jedi/evaluate/param.py b/jedi/evaluate/param.py
index c68986fe..e95eb08e 100644
--- a/jedi/evaluate/param.py
+++ b/jedi/evaluate/param.py
@@ -94,6 +94,26 @@ class Arguments(pr.Base):
             new_args.append(stmt)
         return new_args
 
+    def eval_argument_clinic(self, arguments):
+        """Uses a list with argument clinic information (see PEP 436)."""
+        iterator = self.unpack()
+        for i, (name, optional, allow_kwargs) in enumerate(arguments):
+            key, va_values = next(iterator, (None, []))
+            if key is not None:
+                raise NotImplementedError
+            if not va_values and not optional:
+                debug.warning('TypeError: %s expected at least %s arguments, got %s',
+                              name, len(arguments), i)
+                raise ValueError
+            values = list(chain.from_iterable(self._evaluator.eval_element(el)
+                                              for el in va_values))
+            if not values and not optional:
+                # For the stdlib we always want values. If we don't get them,
+                # that's ok, maybe something is too hard to resolve, however,
+                # we will not proceed with the evaluation of that function. 
+                raise ValueError
+            yield values
+
     def eval_args(self):
         return [self._evaluator.eval_element(el) for stars, el in self._split()]
 
diff --git a/jedi/evaluate/stdlib.py b/jedi/evaluate/stdlib.py
index f45816a1..fef96adf 100644
--- a/jedi/evaluate/stdlib.py
+++ b/jedi/evaluate/stdlib.py
@@ -7,6 +7,8 @@ To add a new implementation, create a function and add it to the
 
 """
 import collections
+import re
+
 from jedi._compatibility import unicode
 from jedi.evaluate import compiled
 from jedi.evaluate import representation as er
@@ -58,15 +60,30 @@ def argument_clinic(string, want_obj=False):
     """
     Works like Argument Clinic (PEP 436), to validate function params.
     """
-    args = []
-    # TODO Do the splitting and checking if the input is correct.
-    #re.
-    # = string.split(', ')
+    clinic_args = []
+    allow_kwargs = False
+    while string:
+        # Optional arguments have to begin with a bracket. And should always be
+        # at the end of the arguments. This is therefore not a proper argument
+        # clinic implementation. `range()` for exmple allows an optional start
+        # value at the beginning.
+        match = re.match('(?:(?:(\[), ?|, ?|)(\w+)|, ?/)\]*', string)
+        string = string[len(match.group(0)):]
+        if not match.group(2):  # A slash -> allow named arguments
+            allow_kwargs = True
+            continue
+        optional = match.group(1)
+        word = match.group(2)
+        clinic_args.append((word, bool(optional), allow_kwargs))
 
     def f(func):
         def wrapper(evaluator, obj, arguments):
-            args = arguments.eval_args()
-            return func(evaluator, *args)
+            try:
+                lst = list(arguments.eval_argument_clinic(clinic_args))
+            except ValueError:
+                return []
+            else:
+                return func(evaluator, *lst)
 
         return wrapper
     return f