diff --git a/src/gallium/drivers/radeonsi/si_buffer.c b/src/gallium/drivers/radeonsi/si_buffer.c
index 4ae1b743370..9f017236be1 100644
--- a/src/gallium/drivers/radeonsi/si_buffer.c
+++ b/src/gallium/drivers/radeonsi/si_buffer.c
@@ -641,6 +641,7 @@ static struct pipe_resource *si_buffer_from_user_memory(struct pipe_screen *scre
    }
 
    buf->gpu_address = ws->buffer_get_virtual_address(buf->buf);
+   buf->bo_size = templ->width0;
    return &buf->b.b;
 }