diff --git a/README.md b/README.md
index e6f5d0d5..7646d3a8 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,8 @@
 
 # Synopsis
 
+[![Join the chat at https://gitter.im/boostorg/python](https://badges.gitter.im/boostorg/python.svg)](https://gitter.im/boostorg/python?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+
 Welcome to Boost.Python, a C++ library which enables seamless interoperability between C++ and the Python programming language. The library includes support for:
 
 * References and Pointers
diff --git a/doc/tutorial.qbk b/doc/tutorial.qbk
index b3dcfc94..71d25850 100644
--- a/doc/tutorial.qbk
+++ b/doc/tutorial.qbk
@@ -1871,36 +1871,6 @@ This technique has several advantages:
 * Minimize the need to recompile
 * Rapid prototyping (you can move the code to C++ if required without changing the interface)
 
-You can even add a little syntactic sugar with the use of metaclasses. Let's
-create a special metaclass that "injects" methods in other classes.
-
-    # The one Boost.Python uses for all wrapped classes.
-    # You can use here any class exported by Boost instead of "point"
-    BoostPythonMetaclass = point.__class__
-
-    class injector(object):
-        class __metaclass__(BoostPythonMetaclass):
-            def __init__(self, name, bases, dict):
-                for b in bases:
-                    if type(b) not in (self, type):
-                        for k,v in dict.items():
-                            setattr(b,k,v)
-                return type.__init__(self, name, bases, dict)
-
-    # inject some methods in the point foo
-    class more_point(injector, point):
-        def __repr__(self):
-            return 'Point(x=%s, y=%s)' % (self.x, self.y)
-        def foo(self):
-            print 'foo!'
-
-Now let's see how it got:
-
-    >>> print point()
-    Point(x=10, y=10)
-    >>> point().foo()
-    foo!
-
 Another useful idea is to replace constructors with factory functions:
 
     _point = point
diff --git a/include/boost/python/numpy/config.hpp b/include/boost/python/numpy/config.hpp
index e6484bc5..f70b94cb 100644
--- a/include/boost/python/numpy/config.hpp
+++ b/include/boost/python/numpy/config.hpp
@@ -62,7 +62,9 @@
 // Set the name of our library, this will get undef'ed by auto_link.hpp
 // once it's done with it:
 //
-#define BOOST_LIB_NAME boost_numpy##PY_MAJOR_VERSION##PY_MINOR_VERSION
+#define _BOOST_PYTHON_CONCAT(N, M, m) N ## M ## m
+#define BOOST_PYTHON_CONCAT(N, M, m) _BOOST_PYTHON_CONCAT(N, M, m)
+#define BOOST_LIB_NAME BOOST_PYTHON_CONCAT(boost_numpy, PY_MAJOR_VERSION, PY_MINOR_VERSION)
 //
 // If we're importing code from a dll, then tell auto_link.hpp about it:
 //
@@ -75,6 +77,9 @@
 #include <boost/config/auto_link.hpp>
 #endif  // auto-linking disabled
 
+#undef BOOST_PYTHON_CONCAT
+#undef _BOOST_PYTHON_CONCAT
+
 #define NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION
 
 #endif // CONFIG_NUMPY20170215_H_
diff --git a/src/numpy/numpy.cpp b/src/numpy/numpy.cpp
index 8e259bc7..3ae2295e 100644
--- a/src/numpy/numpy.cpp
+++ b/src/numpy/numpy.cpp
@@ -19,6 +19,7 @@ static void wrap_import_array()
 static void * wrap_import_array()
 {
   import_array();
+  return NULL;
 }
 #endif
 
diff --git a/src/object/class.cpp b/src/object/class.cpp
index aeef688e..9bb9683a 100644
--- a/src/object/class.cpp
+++ b/src/object/class.cpp
@@ -618,7 +618,7 @@ namespace objects
   {
       object property(
           (python::detail::new_reference)
-          PyObject_CallFunction((PyObject*)&PyProperty_Type, const_cast<char*>("Osss"), fget.ptr(), 0, 0, docstr));
+          PyObject_CallFunction((PyObject*)&PyProperty_Type, const_cast<char*>("Osss"), fget.ptr(), (char*)NULL, (char*)NULL, docstr));
       
       this->setattr(name, property);
   }
@@ -628,7 +628,7 @@ namespace objects
   {
       object property(
           (python::detail::new_reference)
-          PyObject_CallFunction((PyObject*)&PyProperty_Type, const_cast<char*>("OOss"), fget.ptr(), fset.ptr(), 0, docstr));
+          PyObject_CallFunction((PyObject*)&PyProperty_Type, const_cast<char*>("OOss"), fget.ptr(), fset.ptr(), (char*)NULL, docstr));
       
       this->setattr(name, property);
   }