diff --git a/src/northbridge/amd/agesa/family15/northbridge.c b/src/northbridge/amd/agesa/family15/northbridge.c
index b0fc91d7a5..d1a322ca6c 100644
--- a/src/northbridge/amd/agesa/family15/northbridge.c
+++ b/src/northbridge/amd/agesa/family15/northbridge.c
@@ -28,6 +28,7 @@
 #include <string.h>
 #include <bitops.h>
 #include <cpu/cpu.h>
+#include <cbmem.h>
 
 #include <cpu/x86/lapic.h>
 
@@ -624,10 +625,7 @@ static struct hw_mem_hole_info get_hw_mem_hole_info(void)
 	return mem_hole;
 }
 #endif
-#if CONFIG_WRITE_HIGH_TABLES==1
-#define HIGH_TABLES_SIZE 64	// maximum size of high tables in KB
-extern uint64_t high_tables_base, high_tables_size;
-#endif
+
 #if CONFIG_GFXUMA == 1
 extern uint64_t uma_memory_base, uma_memory_size;
 static void add_uma_resource(struct device *dev, int index)
@@ -779,13 +777,13 @@ static void domain_set_resources(device_t dev)
 					if (high_tables_base==0) {
 						/* Leave some space for ACPI, PIRQ and MP tables */
 #if CONFIG_GFXUMA == 1
-						high_tables_base = uma_memory_base - (HIGH_TABLES_SIZE * 1024);
+						high_tables_base = uma_memory_base - HIGH_MEMORY_SIZE;
 #else
-						high_tables_base = (mmio_basek - HIGH_TABLES_SIZE) * 1024;
+						high_tables_base = (mmio_basek * 1024) - HIGH_MEMORY_SIZE;
 #endif
-						high_tables_size = HIGH_TABLES_SIZE * 1024;
+						high_tables_size = HIGH_MEMORY_SIZE;
 						printk(BIOS_DEBUG, " split: %dK table at =%08llx\n",
-							 HIGH_TABLES_SIZE, high_tables_base);
+							 (u32)(high_tables_size / 1024), high_tables_base);
 					}
 #endif
 				}
@@ -813,11 +811,11 @@ static void domain_set_resources(device_t dev)
 		if (high_tables_base==0) {
 			/* Leave some space for ACPI, PIRQ and MP tables */
 #if CONFIG_GFXUMA == 1
-			high_tables_base = uma_memory_base - (HIGH_TABLES_SIZE * 1024);
+			high_tables_base = uma_memory_base - HIGH_MEMORY_SIZE;
 #else
-			high_tables_base = (limitk - HIGH_TABLES_SIZE) * 1024;
+			high_tables_base = (limitk * 1024) - HIGH_MEMORY_SIZE;
 #endif
-			high_tables_size = HIGH_TABLES_SIZE * 1024;
+			high_tables_size = HIGH_MEMORY_SIZE;
 		}
 #endif
 	}