diff --git a/dlls/d3d8/buffer.c b/dlls/d3d8/buffer.c
index 24045068705..8116c1b87b8 100644
--- a/dlls/d3d8/buffer.c
+++ b/dlls/d3d8/buffer.c
@@ -490,7 +490,7 @@ static HRESULT WINAPI d3d8_indexbuffer_Unlock(IDirect3DIndexBuffer8 *iface)
     TRACE("iface %p.\n", iface);
 
     wined3d_mutex_lock();
-    wined3d_buffer_unmap(buffer->wined3d_buffer);
+    wined3d_resource_unmap(wined3d_buffer_get_resource(buffer->wined3d_buffer), 0);
     wined3d_mutex_unlock();
 
     return D3D_OK;