diff --git a/include/Makefile.in b/include/Makefile.in
index acb55b37f6c..a869ae4bc73 100644
--- a/include/Makefile.in
+++ b/include/Makefile.in
@@ -777,6 +777,7 @@ SOURCES = \
 	windows.globalization.idl \
 	windows.h \
 	windows.media.devices.idl \
+	windows.media.idl \
 	windows.media.speechsynthesis.idl \
 	windows.storage.streams.idl \
 	windows.system.idl \
diff --git a/include/windows.foundation.idl b/include/windows.foundation.idl
index fe09dc66edd..292522f2c49 100644
--- a/include/windows.foundation.idl
+++ b/include/windows.foundation.idl
@@ -119,6 +119,15 @@ namespace Windows {
         {
             HRESULT ToString([out, retval] HSTRING *value);
         }
+
+        [
+            contract(Windows.Foundation.FoundationContract, 1.0),
+            uuid(30d5a829-7fa4-4026-83bb-d75bae4ea99e)
+        ]
+        interface IClosable : IInspectable
+        {
+            HRESULT Close();
+        }
     }
 }
 
diff --git a/include/windows.media.idl b/include/windows.media.idl
new file mode 100644
index 00000000000..fe81c768361
--- /dev/null
+++ b/include/windows.media.idl
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2021 Paul Gofman 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
+ */
+
+#ifdef __WIDL__
+#pragma winrt ns_prefix
+#endif
+
+import "inspectable.idl";
+import "windows.foundation.idl";
+
+namespace Windows {
+    namespace Media {
+        interface IMediaControl;
+    }
+}
+
+namespace Windows {
+    namespace Media {
+        [contract(Windows.Foundation.UniversalApiContract, 1.0)]
+        [uuid(1803def8-dca5-4b6f-9c20-e3d3c0643625)]
+        interface IMediaMarker : IInspectable
+        {
+            [propget] HRESULT Time([out] [retval] Windows.Foundation.TimeSpan* value);
+            [propget] HRESULT MediaMarkerType([out] [retval] HSTRING* value);
+            [propget] HRESULT Text([out] [retval] HSTRING* value);
+        }
+    }
+}
diff --git a/include/windows.media.speechsynthesis.idl b/include/windows.media.speechsynthesis.idl
index af4466681dc..29dca510dee 100644
--- a/include/windows.media.speechsynthesis.idl
+++ b/include/windows.media.speechsynthesis.idl
@@ -22,6 +22,7 @@
 
 import "inspectable.idl";
 import "windows.foundation.idl";
+import "windows.media.idl";
 
 namespace Windows {
     namespace Foundation {
@@ -35,10 +36,27 @@ namespace Windows {
             interface ISpeechSynthesizer;
             interface ISpeechSynthesizer2;
             interface IVoiceInformation;
+            interface ISpeechSynthesisStream;
             runtimeclass SpeechSynthesizer;
             runtimeclass VoiceInformation;
+            runtimeclass SpeechSynthesisStream;
         }
     }
+    namespace Storage {
+        namespace Streams {
+            interface IRandomAccessStreamWithContentType;
+            interface IRandomAccessStream;
+            interface IInputStream;
+            interface IOutputStream;
+            interface IContentTypeProvider;
+        }
+    }
+}
+
+namespace Windows {
+    namespace Media {
+        interface IMediaMarker;
+    }
 }
 
 namespace Windows {
@@ -48,6 +66,9 @@ namespace Windows {
                 interface Windows.Foundation.Collections.IIterator<Windows.Media.SpeechSynthesis.VoiceInformation*>;
                 interface Windows.Foundation.Collections.IIterable<Windows.Media.SpeechSynthesis.VoiceInformation*>;
                 interface Windows.Foundation.Collections.IVectorView<Windows.Media.SpeechSynthesis.VoiceInformation*>;
+                interface Windows.Foundation.Collections.IVectorView<Windows.Media.IMediaMarker*>;
+                interface Windows.Foundation.IAsyncOperation<Windows.Media.SpeechSynthesis.SpeechSynthesisStream*>;
+                interface Windows.Foundation.AsyncOperationCompletedHandler<Windows.Media.SpeechSynthesis.SpeechSynthesisStream*>;
             }
         }
     }
@@ -63,6 +84,34 @@ namespace Windows {
                 Female = 1
             };
 
+            [contract(Windows.Foundation.UniversalApiContract, 1.0)]
+            [exclusiveto(Windows.Media.SpeechSynthesis.SpeechSynthesisStream)]
+            [uuid(83e46e93-244c-4622-ba0b-6229c4d0d65d)]
+            interface ISpeechSynthesisStream : IInspectable
+                requires
+                    Windows.Storage.Streams.IRandomAccessStreamWithContentType,
+                    Windows.Storage.Streams.IRandomAccessStream,
+                    Windows.Foundation.IClosable,
+                    Windows.Storage.Streams.IInputStream,
+                    Windows.Storage.Streams.IOutputStream,
+                    Windows.Storage.Streams.IContentTypeProvider
+            {
+                [propget] HRESULT Markers([out] [retval] Windows.Foundation.Collections.IVectorView<Windows.Media.IMediaMarker*>** value);
+            }
+
+            [
+                contract(Windows.Foundation.UniversalApiContract, 1.0),
+                exclusiveto(Windows.Media.SpeechSynthesis.SpeechSynthesizer),
+                uuid(ce9f7c76-97f4-4ced-ad68-d51c458e45c6)
+            ]
+            interface ISpeechSynthesizer : IInspectable
+            {
+                HRESULT SynthesizeTextToStreamAsync([in] HSTRING text, [out] [retval] Windows.Foundation.IAsyncOperation<Windows.Media.SpeechSynthesis.SpeechSynthesisStream*> **operation);
+                HRESULT SynthesizeSsmlToStreamAsync([in] HSTRING Ssml, [out] [retval] Windows.Foundation.IAsyncOperation<Windows.Media.SpeechSynthesis.SpeechSynthesisStream*> **operation);
+                [propput] HRESULT Voice([in] VoiceInformation *value);
+                [propget] HRESULT Voice([out] [retval] VoiceInformation **value);
+            }
+
             [
                 contract(Windows.Foundation.UniversalApiContract, 1.0),
                 exclusiveto(Windows.Media.SpeechSynthesis.VoiceInformation),
@@ -97,6 +146,20 @@ namespace Windows {
                 [default] interface Windows.Media.SpeechSynthesis.IVoiceInformation;
             }
 
+
+            [contract(Windows.Foundation.UniversalApiContract, 1.0)]
+            [marshaling_behavior(agile)]
+            runtimeclass SpeechSynthesisStream
+            {
+                [default] interface Windows.Media.SpeechSynthesis.ISpeechSynthesisStream;
+                interface Windows.Storage.Streams.IRandomAccessStreamWithContentType;
+                interface Windows.Storage.Streams.IContentTypeProvider;
+                interface Windows.Storage.Streams.IRandomAccessStream;
+                interface Windows.Storage.Streams.IOutputStream;
+                interface Windows.Foundation.IClosable;
+                interface Windows.Storage.Streams.IInputStream;
+            }
+
             [
                 activatable(Windows.Foundation.UniversalApiContract, 1.0),
                 contract(Windows.Foundation.UniversalApiContract, 1.0),