diff --git a/src/northbridge/amd/gx2/northbridgeinit.c b/src/northbridge/amd/gx2/northbridgeinit.c
index 136dcf2e02..0cb7803259 100644
--- a/src/northbridge/amd/gx2/northbridgeinit.c
+++ b/src/northbridge/amd/gx2/northbridgeinit.c
@@ -548,7 +548,7 @@ static void rom_shadow_settings(void)
  * SYSRC(7:0) = 00h 		 ; writeback, can set to 08h to make writethrough
  */
 #define SYSMEM_RCONF_WRITETHROUGH 8
-#define DEVRC_RCONF_DEFAULT 0x21
+#define DEVRC_RCONF_DEFAULT 0x21ul
 #define ROMBASE_RCONF_DEFAULT 0xFFFC0000
 #define ROMRC_RCONF_DEFAULT 0x25
 
diff --git a/src/northbridge/amd/lx/northbridgeinit.c b/src/northbridge/amd/lx/northbridgeinit.c
index 82b3f48e8e..b4e1d4a080 100644
--- a/src/northbridge/amd/lx/northbridgeinit.c
+++ b/src/northbridge/amd/lx/northbridgeinit.c
@@ -602,7 +602,7 @@ static void rom_shadow_settings(void)
  *
  ***************************************************************************/
 #define SYSMEM_RCONF_WRITETHROUGH 8
-#define DEVRC_RCONF_DEFAULT 0x21
+#define DEVRC_RCONF_DEFAULT 0x21ul
 #define ROMBASE_RCONF_DEFAULT 0xFFFC0000
 #define ROMRC_RCONF_DEFAULT 0x25