diff --git a/include/Makefile.in b/include/Makefile.in
index 6ab53a95af7..6aff236a7c4 100644
--- a/include/Makefile.in
+++ b/include/Makefile.in
@@ -18,6 +18,7 @@ SOURCES = \
 	appcompatapi.h \
 	appmgmt.h \
 	appmodel.h \
+	asferr.h \
 	asptlb.idl \
 	asynot.idl \
 	asysta.idl \
diff --git a/include/asferr.h b/include/asferr.h
new file mode 100644
index 00000000000..5d60c9947f4
--- /dev/null
+++ b/include/asferr.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2020 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
+ */
+
+#ifndef _ASFERR_H
+#define _ASFERR_H
+
+#ifdef RC_INVOKED
+#define _ASF_HRESULT_TYPEDEF_(x) x
+#else
+#define _ASF_HRESULT_TYPEDEF_(x) ((HRESULT)x)
+#endif
+
+#define ASF_S_OPAQUEPACKET                  _ASF_HRESULT_TYPEDEF_(0x000d07f0)
+
+#define ASF_E_BUFFEROVERRUN                 _ASF_HRESULT_TYPEDEF_(0xc00d07d0)
+#define ASF_E_BUFFERTOOSMALL                _ASF_HRESULT_TYPEDEF_(0xc00d07d1)
+#define ASF_E_BADLANGUAGEID                 _ASF_HRESULT_TYPEDEF_(0xc00d07d2)
+#define ASF_E_NOPAYLOADLENGTH               _ASF_HRESULT_TYPEDEF_(0xc00d07db)
+#define ASF_E_TOOMANYPAYLOADS               _ASF_HRESULT_TYPEDEF_(0xc00d07dc)
+#define ASF_E_PACKETCONTENTTOOLARGE         _ASF_HRESULT_TYPEDEF_(0xc00d07de)
+#define ASF_E_UNKNOWNPACKETSIZE             _ASF_HRESULT_TYPEDEF_(0xc00d07e0)
+#define ASF_E_INVALIDHEADER                 _ASF_HRESULT_TYPEDEF_(0xc00d07e2)
+#define ASF_E_NOCLOCKOBJECT                 _ASF_HRESULT_TYPEDEF_(0xc00d07e6)
+#define ASF_E_UNKNOWNCLOCKTYPE              _ASF_HRESULT_TYPEDEF_(0xc00d07eb)
+#define ASF_E_OPAQUEPACKET                  _ASF_HRESULT_TYPEDEF_(0xc00d07ed)
+#define ASF_E_WRONGVERSION                  _ASF_HRESULT_TYPEDEF_(0xc00d07ee)
+#define ASF_E_OVERFLOW                      _ASF_HRESULT_TYPEDEF_(0xc00d07ef)
+#define ASF_E_NOTFOUND                      _ASF_HRESULT_TYPEDEF_(0xc00d07f0)
+#define ASF_E_OBJECTTOOBIG                  _ASF_HRESULT_TYPEDEF_(0xc00d07f3)
+#define ASF_E_UNEXPECTEDVALUE               _ASF_HRESULT_TYPEDEF_(0xc00d07f4)
+#define ASF_E_INVALIDSTATE                  _ASF_HRESULT_TYPEDEF_(0xc00d07f5)
+#define ASF_E_NOLIBRARY                     _ASF_HRESULT_TYPEDEF_(0xc00d07f6)
+#define ASF_E_ALREADYINITIALIZED            _ASF_HRESULT_TYPEDEF_(0xc00d07f7)
+#define ASF_E_INVALIDINIT                   _ASF_HRESULT_TYPEDEF_(0xc00d07f8)
+#define ASF_E_NOHEADEROBJECT                _ASF_HRESULT_TYPEDEF_(0xc00d07f9)
+#define ASF_E_NODATAOBJECT                  _ASF_HRESULT_TYPEDEF_(0xc00d07fa)
+#define ASF_E_NOINDEXOBJECT                 _ASF_HRESULT_TYPEDEF_(0xc00d07fb)
+#define ASF_E_NOSTREAMPROPS                 _ASF_HRESULT_TYPEDEF_(0xc00d07fc)
+#define ASF_E_NOFILEPROPS                   _ASF_HRESULT_TYPEDEF_(0xc00d07fd)
+#define ASF_E_NOLANGUAGELIST                _ASF_HRESULT_TYPEDEF_(0xc00d07fe)
+#define ASF_E_NOINDEXPARAMETERS             _ASF_HRESULT_TYPEDEF_(0xc00d07ff)
+#define ASF_E_UNSUPPORTEDERRORCONCEALMENT   _ASF_HRESULT_TYPEDEF_(0xc00d0800)
+#define ASF_E_INVALIDFLAGS                  _ASF_HRESULT_TYPEDEF_(0xc00d0801)
+#define ASF_E_BADDATADESCRIPTOR             _ASF_HRESULT_TYPEDEF_(0xc00d0802)
+#define ASF_E_BADINDEXINTERVAL              _ASF_HRESULT_TYPEDEF_(0xc00d0803)
+#define ASF_E_INVALIDTIME                   _ASF_HRESULT_TYPEDEF_(0xc00d0804)
+#define ASF_E_INVALIDINDEX                  _ASF_HRESULT_TYPEDEF_(0xc00d0805)
+#define ASF_E_STREAMNUMBERINUSE             _ASF_HRESULT_TYPEDEF_(0xc00d0806)
+#define ASF_E_BADMEDIATYPE                  _ASF_HRESULT_TYPEDEF_(0xc00d0807)
+#define ASF_E_WRITEFAILED                   _ASF_HRESULT_TYPEDEF_(0xc00d0808)
+#define ASF_E_NOTENOUGHDESCRIPTORS          _ASF_HRESULT_TYPEDEF_(0xc00d0809)
+#define ASF_E_INDEXBLOCKUNLOADED            _ASF_HRESULT_TYPEDEF_(0xc00d080a)
+#define ASF_E_NOTENOUGHBANDWIDTH            _ASF_HRESULT_TYPEDEF_(0xc00d080b)
+#define ASF_E_EXCEEDEDMAXIMUMOBJECTSIZE     _ASF_HRESULT_TYPEDEF_(0xc00d080c)
+#define ASF_E_BADDATAUNIT                   _ASF_HRESULT_TYPEDEF_(0xc00d080d)
+#define ASF_E_HEADERSIZE                    _ASF_HRESULT_TYPEDEF_(0xc00d080e)
+
+#endif
diff --git a/include/wmsdk.h b/include/wmsdk.h
index b5528a889b3..6d6fd926ccd 100644
--- a/include/wmsdk.h
+++ b/include/wmsdk.h
@@ -20,7 +20,5 @@
 /* #include <winapifamily.h> */
 
 #include "wmsdkidl.h"
-
-/* Currently unimplemented */
-/* #include "asferr.h" */
+#include "asferr.h"
 #include "nserror.h"