diff --git a/Modules/errnomodule.c b/Modules/errnomodule.c
index 227e24b..d5fe460 100644
--- a/Modules/errnomodule.c
+++ b/Modules/errnomodule.c
@@ -6,7 +6,7 @@
 /* Windows socket errors (WSA*)  */
 #ifdef MS_WINDOWS
 #define WIN32_LEAN_AND_MEAN
-#include <winsock.h>
+#include <windows.h>
 #endif
 
 /*
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 3f94ebc..b948132 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -2628,7 +2628,7 @@
 Shut down the reading side of the socket (flag == SHUT_RD), the writing side\n\
 of the socket (flag == SHUT_WR), or both ends (flag == SHUT_RDWR).");
 
-#ifdef MS_WINDOWS
+#if defined(MS_WINDOWS) && defined(SIO_RCVALL)
 static PyObject*
 sock_ioctl(PySocketSockObject *s, PyObject *arg)
 {
@@ -2677,7 +2677,7 @@
 			  METH_NOARGS, getsockname_doc},
 	{"getsockopt",	  (PyCFunction)sock_getsockopt, METH_VARARGS,
 			  getsockopt_doc},
-#ifdef MS_WINDOWS
+#if defined(MS_WINDOWS) && defined(SIO_RCVALL)
 	{"ioctl",	  (PyCFunction)sock_ioctl, METH_VARARGS,
 			  sock_ioctl_doc},
 #endif
diff --git a/Modules/socketmodule.h b/Modules/socketmodule.h
index 114084c..a24110f 100644
--- a/Modules/socketmodule.h
+++ b/Modules/socketmodule.h
@@ -13,20 +13,23 @@
 # endif
 
 #else /* MS_WINDOWS */
-#if _MSC_VER >= 1300
 # include <winsock2.h>
 # include <ws2tcpip.h>
-# include <MSTcpIP.h> /* for SIO_RCVALL */
-# define HAVE_ADDRINFO
-# define HAVE_SOCKADDR_STORAGE
-# define HAVE_GETADDRINFO
-# define HAVE_GETNAMEINFO
-# define ENABLE_IPV6
-#else
-# define WIN32_LEAN_AND_MEAN
-# include <winsock.h>
-#endif
-#endif
+/* VC6 is shipped with old platform headers, and does not have MSTcpIP.h
+ * Separate SDKs have all the functions we want, but older ones don't have
+ * any version information. I use IPPROTO_IPV6 to detect a decent SDK.
+ */
+# ifdef IPPROTO_IPV6
+#  include <MSTcpIP.h> /* for SIO_RCVALL */
+#  define HAVE_ADDRINFO
+#  define HAVE_SOCKADDR_STORAGE
+#  define HAVE_GETADDRINFO
+#  define HAVE_GETNAMEINFO
+#  define ENABLE_IPV6
+# else
+typedef int socklen_t;
+# endif /* IPPROTO_IPV6 */
+#endif /* MS_WINDOWS */
 
 #ifdef HAVE_SYS_UN_H
 # include <sys/un.h>