diff --git a/common/hw-pci-dev.ads b/common/hw-pci-dev.ads
index b08f9ab..90ed9e5 100644
--- a/common/hw-pci-dev.ads
+++ b/common/hw-pci-dev.ads
@@ -36,12 +36,15 @@
    with
       Pre => Offset mod 4 = 0;
 
+   pragma Warnings (GNATprove, Off, "unused variable ""WC""*",
+                    Reason => "Used for a common interface");
    procedure Map
      (Addr     :    out Word64;
       Res      : in     Resource;
       Length   : in     Natural := 0;
       Offset   : in     Natural := 0;
       WC       : in     Boolean := False);
+   pragma Warnings (GNATprove, On, "unused variable ""WC""*");
 
    procedure Resource_Size (Length : out Natural; Res : Resource);