diff --git a/docs/api.rst b/docs/api.rst
index 6144ab9d1..5bd979ec0 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -90,7 +90,7 @@ Core
       ... class C(object):
       ...     x = attr.ib()
       >>> attr.fields(C).x
-      Attribute(name='x', default=NOTHING, validator=None, repr=True, cmp=True, hash=None, init=True, convert=None, metadata=mappingproxy({}), type=None)
+      Attribute(name='x', default=NOTHING, validator=None, repr=True, cmp=True, hash=None, init=True, convert=None, metadata=mappingproxy({}), type=None, kw_only=False)
 
 
 .. autofunction:: attr.make_class
@@ -202,9 +202,9 @@ Helpers
       ...     x = attr.ib()
       ...     y = attr.ib()
       >>> attr.fields(C)
-      (Attribute(name='x', default=NOTHING, validator=None, repr=True, cmp=True, hash=None, init=True, convert=None, metadata=mappingproxy({}), type=None), Attribute(name='y', default=NOTHING, validator=None, repr=True, cmp=True, hash=None, init=True, convert=None, metadata=mappingproxy({}), type=None))
+      (Attribute(name='x', default=NOTHING, validator=None, repr=True, cmp=True, hash=None, init=True, convert=None, metadata=mappingproxy({}), type=None, kw_only=False), Attribute(name='y', default=NOTHING, validator=None, repr=True, cmp=True, hash=None, init=True, convert=None, metadata=mappingproxy({}), type=None, kw_only=False))
       >>> attr.fields(C)[1]
-      Attribute(name='y', default=NOTHING, validator=None, repr=True, cmp=True, hash=None, init=True, convert=None, metadata=mappingproxy({}), type=None)
+      Attribute(name='y', default=NOTHING, validator=None, repr=True, cmp=True, hash=None, init=True, convert=None, metadata=mappingproxy({}), type=None, kw_only=False)
       >>> attr.fields(C).y is attr.fields(C)[1]
       True
 
@@ -299,7 +299,7 @@ See :ref:`asdict` for examples.
       >>> attr.validate(i)
       Traceback (most recent call last):
          ...
-      TypeError: ("'x' must be <type 'int'> (got '1' that is a <type 'str'>).", Attribute(name='x', default=NOTHING, validator=<instance_of validator for type <type 'int'>>, repr=True, cmp=True, hash=None, init=True, type=None), <type 'int'>, '1')
+      TypeError: ("'x' must be <type 'int'> (got '1' that is a <type 'str'>).", Attribute(name='x', default=NOTHING, validator=<instance_of validator for type <type 'int'>>, repr=True, cmp=True, hash=None, init=True, type=None, kw_only=False), <type 'int'>, '1')
 
 
 Validators can be globally disabled if you want to run them only in development and tests but not in production because you fear their performance impact:
@@ -332,11 +332,11 @@ Validators
       >>> C("42")
       Traceback (most recent call last):
          ...
-      TypeError: ("'x' must be <type 'int'> (got '42' that is a <type 'str'>).", Attribute(name='x', default=NOTHING, validator=<instance_of validator for type <type 'int'>>, type=None), <type 'int'>, '42')
+      TypeError: ("'x' must be <type 'int'> (got '42' that is a <type 'str'>).", Attribute(name='x', default=NOTHING, validator=<instance_of validator for type <type 'int'>>, type=None, kw_only=False), <type 'int'>, '42')
       >>> C(None)
       Traceback (most recent call last):
          ...
-      TypeError: ("'x' must be <type 'int'> (got None that is a <type 'NoneType'>).", Attribute(name='x', default=NOTHING, validator=<instance_of validator for type <type 'int'>>, repr=True, cmp=True, hash=None, init=True, type=None), <type 'int'>, None)
+      TypeError: ("'x' must be <type 'int'> (got None that is a <type 'NoneType'>).", Attribute(name='x', default=NOTHING, validator=<instance_of validator for type <type 'int'>>, repr=True, cmp=True, hash=None, init=True, type=None, kw_only=False), <type 'int'>, None)
 
 .. autofunction:: attr.validators.in_
 
@@ -388,7 +388,7 @@ Validators
       >>> C("42")
       Traceback (most recent call last):
          ...
-      TypeError: ("'x' must be <type 'int'> (got '42' that is a <type 'str'>).", Attribute(name='x', default=NOTHING, validator=<instance_of validator for type <type 'int'>>, type=None), <type 'int'>, '42')
+      TypeError: ("'x' must be <type 'int'> (got '42' that is a <type 'str'>).", Attribute(name='x', default=NOTHING, validator=<instance_of validator for type <type 'int'>>, type=None, kw_only=False), <type 'int'>, '42')
       >>> C(None)
       C(x=None)
 
diff --git a/docs/examples.rst b/docs/examples.rst
index 84237c724..5a6fe803d 100644
--- a/docs/examples.rst
+++ b/docs/examples.rst
@@ -185,7 +185,7 @@ If you omit ``kw_only`` or specify ``kw_only=False``, then you'll get an error:
     ... class A:
     ...     a = attr.ib(default=0)
     >>> @attr.s
-    ... class B(Base):
+    ... class B(A):
     ...     b = attr.ib()
     Traceback (most recent call last):
       ...
@@ -417,7 +417,7 @@ This example also shows of some syntactic sugar for using the :func:`attr.valida
    >>> C("42")
    Traceback (most recent call last):
       ...
-   TypeError: ("'x' must be <type 'int'> (got '42' that is a <type 'str'>).", Attribute(name='x', default=NOTHING, factory=NOTHING, validator=<instance_of validator for type <type 'int'>>, type=None), <type 'int'>, '42')
+   TypeError: ("'x' must be <type 'int'> (got '42' that is a <type 'str'>).", Attribute(name='x', default=NOTHING, factory=NOTHING, validator=<instance_of validator for type <type 'int'>>, type=None, kw_only=False), <type 'int'>, '42')
 
 Of course you can mix and match the two approaches at your convenience:
 
@@ -435,7 +435,7 @@ Of course you can mix and match the two approaches at your convenience:
    >>> C("128")
    Traceback (most recent call last):
       ...
-   TypeError: ("'x' must be <class 'int'> (got '128' that is a <class 'str'>).", Attribute(name='x', default=NOTHING, validator=[<instance_of validator for type <class 'int'>>, <function fits_byte at 0x10fd7a0d0>], repr=True, cmp=True, hash=True, init=True, convert=None, metadata=mappingproxy({}), type=None), <class 'int'>, '128')
+   TypeError: ("'x' must be <class 'int'> (got '128' that is a <class 'str'>).", Attribute(name='x', default=NOTHING, validator=[<instance_of validator for type <class 'int'>>, <function fits_byte at 0x10fd7a0d0>], repr=True, cmp=True, hash=True, init=True, convert=None, metadata=mappingproxy({}), type=None, kw_only=False), <class 'int'>, '128')
    >>> C(256)
    Traceback (most recent call last):
       ...
@@ -450,7 +450,7 @@ And finally you can disable validators globally:
    >>> C("128")
    Traceback (most recent call last):
       ...
-   TypeError: ("'x' must be <class 'int'> (got '128' that is a <class 'str'>).", Attribute(name='x', default=NOTHING, validator=[<instance_of validator for type <class 'int'>>, <function fits_byte at 0x10fd7a0d0>], repr=True, cmp=True, hash=True, init=True, convert=None, metadata=mappingproxy({}), type=None), <class 'int'>, '128')
+   TypeError: ("'x' must be <class 'int'> (got '128' that is a <class 'str'>).", Attribute(name='x', default=NOTHING, validator=[<instance_of validator for type <class 'int'>>, <function fits_byte at 0x10fd7a0d0>], repr=True, cmp=True, hash=True, init=True, convert=None, metadata=mappingproxy({}), type=None, kw_only=False), <class 'int'>, '128')
 
 
 Conversion
diff --git a/docs/extending.rst b/docs/extending.rst
index d460ee9b8..132a4457a 100644
--- a/docs/extending.rst
+++ b/docs/extending.rst
@@ -17,7 +17,7 @@ So it is fairly simple to build your own decorators on top of ``attrs``:
    ... @attr.s
    ... class C(object):
    ...     a = attr.ib()
-   (Attribute(name='a', default=NOTHING, validator=None, repr=True, cmp=True, hash=None, init=True, convert=None, metadata=mappingproxy({}), type=None),)
+   (Attribute(name='a', default=NOTHING, validator=None, repr=True, cmp=True, hash=None, init=True, convert=None, metadata=mappingproxy({}), type=None, kw_only=False),)
 
 
 .. warning::