diff --git a/include/Makefile.in b/include/Makefile.in
index 9796dd8e5d9..a4563920f6c 100644
--- a/include/Makefile.in
+++ b/include/Makefile.in
@@ -188,6 +188,7 @@ SOURCES = \
 	ddk/wdm.h \
 	ddk/winddiui.h \
 	ddk/winsplp.h \
+	ddk/wsk.h \
 	ddraw.h \
 	ddrawgdi.h \
 	ddrawi.h \
diff --git a/include/ddk/wsk.h b/include/ddk/wsk.h
new file mode 100644
index 00000000000..c7100bb7997
--- /dev/null
+++ b/include/ddk/wsk.h
@@ -0,0 +1,116 @@
+/*
+ * Copyright 2020 Alistair Leslie-Hughes
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ */
+#ifndef _INC_WSK
+#define _INC_WSK
+
+#include <winsock2.h>
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+struct _WSK_CLIENT;
+typedef struct _WSK_CLIENT WSK_CLIENT, *PWSK_CLIENT;
+typedef struct _WSK_CLIENT_CONNECTION_DISPATCH WSK_CLIENT_CONNECTION_DISPATCH, *PWSK_CLIENT_CONNECTION_DISPATCH;
+
+typedef struct _WSK_BUF
+{
+    PMDL Mdl;
+    ULONG Offset;
+    SIZE_T Length;
+} WSK_BUF, *PWSK_BUF;
+
+typedef struct _WSK_DATA_INDICATION
+{
+    struct _WSK_DATA_INDICATION *Next;
+    WSK_BUF                      Buffer;
+} WSK_DATA_INDICATION, *PWSK_DATA_INDICATION;
+
+typedef NTSTATUS (WINAPI *PFN_WSK_CLIENT_EVENT)(void *context, ULONG event, void *info, SIZE_T length);
+typedef NTSTATUS (WINAPI *PFN_WSK_DISCONNECT_EVENT)(void *context, ULONG flags);
+typedef NTSTATUS (WINAPI *PFN_WSK_SEND_BACKLOG_EVENT)(void *socket_context, SIZE_T ideal_backlog_size);
+typedef NTSTATUS (WINAPI *PFN_WSK_SOCKET)(WSK_CLIENT *client, ADDRESS_FAMILY family,
+        USHORT type, ULONG protocol, ULONG flags, void *context, const void *dispatch,
+        PEPROCESS process, PETHREAD thread, SECURITY_DESCRIPTOR *security, IRP *irp);
+typedef NTSTATUS (WINAPI *PFN_WSK_SOCKET_CONNECT)(WSK_CLIENT *client, USHORT type,
+        ULONG protocol, SOCKADDR *local, SOCKADDR *remote, ULONG flags, void *context,
+        const WSK_CLIENT_CONNECTION_DISPATCH *dispatch, PEPROCESS process, PETHREAD owning,
+        SECURITY_DESCRIPTOR *descriptor, IRP *irp);
+typedef NTSTATUS (WINAPI *PFN_WSK_CONTROL_CLIENT)(WSK_CLIENT *client, ULONG control,
+        SIZE_T input_size, void *input, SIZE_T output_size, void *output, SIZE_T *returned,
+        IRP *irp);
+typedef NTSTATUS (WINAPI *PFN_WSK_GET_ADDRESS_INFO)(WSK_CLIENT *client, UNICODE_STRING *node_name,
+        UNICODE_STRING *service_name, ULONG name_space, GUID *provider, ADDRINFOEXW *hints,
+        ADDRINFOEXW **result, PEPROCESS process, PETHREAD thread, IRP *irp);
+typedef void (WINAPI *PFN_WSK_FREE_ADDRESS_INFO)(WSK_CLIENT *client, ADDRINFOEXW *addrinfo);
+typedef NTSTATUS (WINAPI *PFN_WSK_GET_NAME_INFO)(WSK_CLIENT *client, SOCKADDR *addr,
+        ULONG length, UNICODE_STRING *node_name, UNICODE_STRING *service_name,
+        ULONG flags, PEPROCESS process, PETHREAD thread, IRP *irp);
+typedef NTSTATUS (WINAPI* PFN_WSK_RECEIVE_EVENT)(void *context, ULONG flags,
+        WSK_DATA_INDICATION *indication, SIZE_T size, SIZE_T *accepted);
+
+typedef struct _WSK_PROVIDER_DISPATCH
+{
+    USHORT Version;
+    USHORT Reserved;
+    PFN_WSK_SOCKET WskSocket;
+    PFN_WSK_SOCKET_CONNECT WskSocketConnect;
+    PFN_WSK_CONTROL_CLIENT WskControlClient;
+    PFN_WSK_GET_ADDRESS_INFO WskGetAddressInfo;
+    PFN_WSK_FREE_ADDRESS_INFO WskFreeAddressInfo;
+    PFN_WSK_GET_NAME_INFO WskGetNameInfo;
+} WSK_PROVIDER_DISPATCH, *PWSK_PROVIDER_DISPATCH;
+
+typedef struct _WSK_CLIENT_CONNECTION_DISPATCH
+{
+    PFN_WSK_RECEIVE_EVENT WskReceiveEvent;
+    PFN_WSK_DISCONNECT_EVENT WskDisconnectEvent;
+    PFN_WSK_SEND_BACKLOG_EVENT WskSendBacklogEvent;
+} WSK_CLIENT_CONNECTION_DISPATCH, *PWSK_CLIENT_CONNECTION_DISPATCH;
+
+typedef struct _WSK_CLIENT_DISPATCH
+{
+    USHORT Version;
+    USHORT Reserved;
+    PFN_WSK_CLIENT_EVENT WskClientEvent;
+} WSK_CLIENT_DISPATCH, *PWSK_CLIENT_DISPATCH;
+
+typedef struct _WSK_CLIENT_NPI
+{
+    void *ClientContext;
+    const WSK_CLIENT_DISPATCH *Dispatch;
+} WSK_CLIENT_NPI, *PWSK_CLIENT_NPI;
+
+typedef struct _WSK_REGISTRATION
+{
+    ULONGLONG ReservedRegistrationState;
+    void *ReservedRegistrationContext;
+    KSPIN_LOCK ReservedRegistrationLock;
+} WSK_REGISTRATION, *PWSK_REGISTRATION;
+
+typedef struct _WSK_PROVIDER_NPI
+{
+    PWSK_CLIENT Client;
+    const WSK_PROVIDER_DISPATCH *Dispatch;
+} WSK_PROVIDER_NPI, *PWSK_PROVIDER_NPI;
+
+#ifdef __cplusplus
+}
+#endif
+#endif