diff --git a/dlls/evr/mixer.c b/dlls/evr/mixer.c
index 1bc4f470401..7663a28ab10 100644
--- a/dlls/evr/mixer.c
+++ b/dlls/evr/mixer.c
@@ -48,6 +48,7 @@ struct video_mixer
     IMFVideoMixerControl2 IMFVideoMixerControl2_iface;
     IMFGetService IMFGetService_iface;
     IMFVideoMixerBitmap IMFVideoMixerBitmap_iface;
+    IMFVideoPositionMapper IMFVideoPositionMapper_iface;
     LONG refcount;
 
     struct input_stream inputs[MAX_MIXER_INPUT_STREAMS];
@@ -89,6 +90,11 @@ static struct video_mixer *impl_from_IMFVideoMixerBitmap(IMFVideoMixerBitmap *if
     return CONTAINING_RECORD(iface, struct video_mixer, IMFVideoMixerBitmap_iface);
 }
 
+static struct video_mixer *impl_from_IMFVideoPositionMapper(IMFVideoPositionMapper *iface)
+{
+    return CONTAINING_RECORD(iface, struct video_mixer, IMFVideoPositionMapper_iface);
+}
+
 static int video_mixer_compare_input_id(const void *a, const void *b)
 {
     const unsigned int *key = a;
@@ -142,6 +148,10 @@ static HRESULT WINAPI video_mixer_transform_QueryInterface(IMFTransform *iface,
     {
         *obj = &mixer->IMFVideoMixerBitmap_iface;
     }
+    else if (IsEqualIID(riid, &IID_IMFVideoPositionMapper))
+    {
+        *obj = &mixer->IMFVideoPositionMapper_iface;
+    }
     else
     {
         WARN("Unsupported interface %s.\n", debugstr_guid(riid));
@@ -858,6 +868,40 @@ static const IMFVideoMixerBitmapVtbl video_mixer_bitmap_vtbl =
     video_mixer_bitmap_GetAlphaBitmapParameters,
 };
 
+static HRESULT WINAPI video_mixer_position_mapper_QueryInterface(IMFVideoPositionMapper *iface, REFIID riid, void **obj)
+{
+    struct video_mixer *mixer = impl_from_IMFVideoPositionMapper(iface);
+    return IMFTransform_QueryInterface(&mixer->IMFTransform_iface, riid, obj);
+}
+
+static ULONG WINAPI video_mixer_position_mapper_AddRef(IMFVideoPositionMapper *iface)
+{
+    struct video_mixer *mixer = impl_from_IMFVideoPositionMapper(iface);
+    return IMFTransform_AddRef(&mixer->IMFTransform_iface);
+}
+
+static ULONG WINAPI video_mixer_position_mapper_Release(IMFVideoPositionMapper *iface)
+{
+    struct video_mixer *mixer = impl_from_IMFVideoPositionMapper(iface);
+    return IMFTransform_Release(&mixer->IMFTransform_iface);
+}
+
+static HRESULT WINAPI video_mixer_position_mapper_MapOutputCoordinateToInputStream(IMFVideoPositionMapper *iface,
+        float x_out, float y_out, DWORD output_stream, DWORD input_stream, float *x_in, float *y_in)
+{
+    FIXME("%p, %f, %f, %u, %u, %p, %p.\n", iface, x_out, y_out, output_stream, input_stream, x_in, y_in);
+
+    return E_NOTIMPL;
+}
+
+static const IMFVideoPositionMapperVtbl video_mixer_position_mapper_vtbl =
+{
+    video_mixer_position_mapper_QueryInterface,
+    video_mixer_position_mapper_AddRef,
+    video_mixer_position_mapper_Release,
+    video_mixer_position_mapper_MapOutputCoordinateToInputStream,
+};
+
 HRESULT WINAPI MFCreateVideoMixer(IUnknown *owner, REFIID riid_device, REFIID riid, void **obj)
 {
     TRACE("%p, %s, %s, %p.\n", owner, debugstr_guid(riid_device), debugstr_guid(riid), obj);
@@ -886,6 +930,7 @@ HRESULT evr_mixer_create(IUnknown *outer, void **out)
     object->IMFVideoMixerControl2_iface.lpVtbl = &video_mixer_control_vtbl;
     object->IMFGetService_iface.lpVtbl = &video_mixer_getservice_vtbl;
     object->IMFVideoMixerBitmap_iface.lpVtbl = &video_mixer_bitmap_vtbl;
+    object->IMFVideoPositionMapper_iface.lpVtbl = &video_mixer_position_mapper_vtbl;
     object->refcount = 1;
     object->input_count = 1;
     video_mixer_init_input(&object->inputs[0]);
diff --git a/dlls/evr/tests/evr.c b/dlls/evr/tests/evr.c
index 4e97f65be09..4f954d868a6 100644
--- a/dlls/evr/tests/evr.c
+++ b/dlls/evr/tests/evr.c
@@ -405,10 +405,8 @@ static void test_default_mixer(void)
     IUnknown_Release(unk);
 
     hr = IMFTransform_QueryInterface(transform, &IID_IMFVideoPositionMapper, (void **)&unk);
-todo_wine
     ok(hr == S_OK, "Unexpected hr %#x.\n", hr);
-    if (SUCCEEDED(hr))
-        IUnknown_Release(unk);
+    IUnknown_Release(unk);
 
     hr = IMFTransform_QueryInterface(transform, &IID_IMFVideoProcessor, (void **)&unk);
 todo_wine