diff --git a/include/Makefile.in b/include/Makefile.in
index 94010695214..a9a478e5433 100644
--- a/include/Makefile.in
+++ b/include/Makefile.in
@@ -832,6 +832,7 @@ SOURCES = \
 	wmsbuffer.idl \
 	wmsdk.h \
 	wmsdkidl.idl \
+	wmsecure.idl \
 	wnaspi32.h \
 	wownt16.h \
 	wownt32.h \
diff --git a/include/wmsecure.idl b/include/wmsecure.idl
new file mode 100644
index 00000000000..f8d731a05ba
--- /dev/null
+++ b/include/wmsecure.idl
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2021 Zebediah Figura for CodeWeavers
+ *
+ * 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
+ */
+
+import "oaidl.idl";
+import "ocidl.idl";
+
+[
+    object,
+    local,
+    uuid(d9b67d36-a9ad-4eb4-baef-db284ef5504c),
+]
+interface IWMAuthorizer : IUnknown
+{
+    HRESULT GetCertCount(DWORD *count);
+    HRESULT GetCert(DWORD index, BYTE **data);
+    HRESULT GetSharedData(DWORD index, const BYTE *data, BYTE *cert, BYTE **ret_data);
+}
+
+[
+    object,
+    local,
+    uuid(2720598a-d0f2-4189-bd10-91c46ef0936f),
+]
+interface IWMSecureChannel : IWMAuthorizer
+{
+    HRESULT WMSC_AddCertificate(IWMAuthorizer *cert);
+    HRESULT WMSC_AddSignature(BYTE *signature, DWORD size);
+    HRESULT WMSC_Connect(IWMSecureChannel *peer);
+    HRESULT WMSC_IsConnected(BOOL *connected);
+    HRESULT WMSC_Disconnect();
+    HRESULT WMSC_GetValidCertificate(BYTE **cert, DWORD *signature);
+    HRESULT WMSC_Encrypt(BYTE *data, DWORD size);
+    HRESULT WMSC_Decrypt(BYTE *data, DWORD size);
+    HRESULT WMSC_Lock();
+    HRESULT WMSC_Unlock();
+    HRESULT WMSC_SetSharedData(DWORD index, BYTE *data);
+}
+
+[
+    object,
+    local,
+    uuid(94bc0598-c3d2-11d3-bedf-00c04f612986),
+]
+interface IWMGetSecureChannel : IUnknown
+{
+    HRESULT GetPeerSecureChannelInterface(IWMSecureChannel **channel);
+}