diff --git a/dlls/d3d11/buffer.c b/dlls/d3d11/buffer.c
index d0655a2c6e9..6fec7842076 100644
--- a/dlls/d3d11/buffer.c
+++ b/dlls/d3d11/buffer.c
@@ -110,25 +110,31 @@ static void STDMETHODCALLTYPE d3d11_buffer_GetDevice(ID3D11Buffer *iface, ID3D11
 static HRESULT STDMETHODCALLTYPE d3d11_buffer_GetPrivateData(ID3D11Buffer *iface,
         REFGUID guid, UINT *data_size, void *data)
 {
-    FIXME("iface %p, guid %s, data_size %p, data %p stub!\n", iface, debugstr_guid(guid), data_size, data);
+    struct d3d_buffer *buffer = impl_from_ID3D11Buffer(iface);
 
-    return E_NOTIMPL;
+    TRACE("iface %p, guid %s, data_size %p, data %p.\n", iface, debugstr_guid(guid), data_size, data);
+
+    return d3d_get_private_data(&buffer->private_store, guid, data_size, data);
 }
 
 static HRESULT STDMETHODCALLTYPE d3d11_buffer_SetPrivateData(ID3D11Buffer *iface,
         REFGUID guid, UINT data_size, const void *data)
 {
-    FIXME("iface %p, guid %s, data_size %u, data %p stub!\n", iface, debugstr_guid(guid), data_size, data);
+    struct d3d_buffer *buffer = impl_from_ID3D11Buffer(iface);
 
-    return E_NOTIMPL;
+    TRACE("iface %p, guid %s, data_size %u, data %p.\n", iface, debugstr_guid(guid), data_size, data);
+
+    return d3d_set_private_data(&buffer->private_store, guid, data_size, data);
 }
 
 static HRESULT STDMETHODCALLTYPE d3d11_buffer_SetPrivateDataInterface(ID3D11Buffer *iface,
         REFGUID guid, const IUnknown *data)
 {
-    FIXME("iface %p, guid %s, data %p stub!\n", iface, debugstr_guid(guid), data);
+    struct d3d_buffer *buffer = impl_from_ID3D11Buffer(iface);
 
-    return E_NOTIMPL;
+    TRACE("iface %p, guid %s, data %p.\n", iface, debugstr_guid(guid), data);
+
+    return d3d_set_private_data_interface(&buffer->private_store, guid, data);
 }
 
 static void STDMETHODCALLTYPE d3d11_buffer_GetType(ID3D11Buffer *iface,