diff --git a/dlls/winegstreamer/wm_reader.c b/dlls/winegstreamer/wm_reader.c
index 85332926d49..09745ae2023 100644
--- a/dlls/winegstreamer/wm_reader.c
+++ b/dlls/winegstreamer/wm_reader.c
@@ -2348,11 +2348,25 @@ static HRESULT WINAPI reader_GetOutputSetting(IWMSyncReader2 *iface, DWORD outpu
     return E_NOTIMPL;
 }
 
-static HRESULT WINAPI reader_GetReadStreamSamples(IWMSyncReader2 *iface, WORD stream_num, BOOL *compressed)
+static HRESULT WINAPI reader_GetReadStreamSamples(IWMSyncReader2 *iface, WORD stream_number, BOOL *compressed)
 {
-    struct wm_reader *This = impl_from_IWMSyncReader2(iface);
-    FIXME("(%p)->(%d %p): stub!\n", This, stream_num, compressed);
-    return E_NOTIMPL;
+    struct wm_reader *reader = impl_from_IWMSyncReader2(iface);
+    struct wm_stream *stream;
+
+    TRACE("reader %p, stream_number %u, compressed %p.\n", reader, stream_number, compressed);
+
+    EnterCriticalSection(&reader->cs);
+
+    if (!(stream = wm_reader_get_stream_by_stream_number(reader, stream_number)))
+    {
+        LeaveCriticalSection(&reader->cs);
+        return E_INVALIDARG;
+    }
+
+    *compressed = stream->read_compressed;
+
+    LeaveCriticalSection(&reader->cs);
+    return S_OK;
 }
 
 static HRESULT WINAPI reader_GetStreamNumberForOutput(IWMSyncReader2 *iface,