diff --git a/common/hw-gfx-gma.ads b/common/hw-gfx-gma.ads
index 5b66803..3771804 100644
--- a/common/hw-gfx-gma.ads
+++ b/common/hw-gfx-gma.ads
@@ -101,6 +101,10 @@
    with
       Pre => Is_Initialized and HW.Config.Dynamic_MMIO;
 
+   procedure Map_Linear_FB (Linear_FB : out Word64; FB : in Framebuffer_Type)
+   with
+      Pre => Is_Initialized and HW.Config.Dynamic_MMIO;
+
 private
 
    ----------------------------------------------------------------------------