diff --git a/include/Makefile.in b/include/Makefile.in
index 8284d6fdf32..b1e7d0084ff 100644
--- a/include/Makefile.in
+++ b/include/Makefile.in
@@ -772,6 +772,7 @@ SOURCES = \
 	wtypes.idl \
 	wuapi.idl \
 	x3daudio.h \
+	xact3wb.h \
 	xapo.idl \
 	xapofx.h \
 	xaudio2.idl \
diff --git a/include/xact3wb.h b/include/xact3wb.h
new file mode 100644
index 00000000000..b4c5a53d40c
--- /dev/null
+++ b/include/xact3wb.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 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 __XACT3WB_H__
+#define __XACT3WB_H__
+
+typedef union WAVEBANKMINIWAVEFORMAT
+{
+    struct
+    {
+        DWORD wFormatTag     :  2;
+        DWORD nChannels      :  3;
+        DWORD nSamplesPerSec : 18;
+        DWORD wBlockAlign    :  8;
+        DWORD wBitsPerSample :  1;
+    } DUMMYSTRUCTNAME;
+    DWORD dwValue;
+} WAVEBANKMINIWAVEFORMAT;
+
+typedef struct WAVEBANKREGION
+{
+    DWORD dwOffset;
+    DWORD dwLength;
+} WAVEBANKREGION;
+
+typedef struct WAVEBANKSAMPLEREGION
+{
+    DWORD dwStartSample;
+    DWORD dwTotalSamples;
+} WAVEBANKSAMPLEREGION;
+
+typedef struct WAVEBANKENTRY
+{
+    union
+    {
+        struct
+        {
+            DWORD dwFlags  :  4;
+            DWORD Duration : 28;
+        } DUMMYSTRUCTNAME;
+        DWORD dwFlagsAndDuration;
+    } DUMMYUNIONNAME;
+
+    WAVEBANKMINIWAVEFORMAT Format;
+    WAVEBANKREGION PlayRegion;
+    WAVEBANKSAMPLEREGION LoopRegion;
+} WAVEBANKENTRY;
+
+#endif /* __XACT3WB_H__ */