diff --git a/cpu/arm720t/cpu.c b/cpu/arm720t/cpu.c
index 60c1aa9..5ac8f59 100644
--- a/cpu/arm720t/cpu.c
+++ b/cpu/arm720t/cpu.c
@@ -41,7 +41,7 @@
 	 * setup up stacks if necessary
 	 */
 #ifdef CONFIG_USE_IRQ
-	IRQ_STACK_START = _armboot_start - CFG_MALLOC_LEN - CFG_GBL_DATA_SIZE - 4;
+	IRQ_STACK_START = _armboot_start - CONFIG_SYS_MALLOC_LEN - CONFIG_SYS_GBL_DATA_SIZE - 4;
 	FIQ_STACK_START = IRQ_STACK_START - CONFIG_STACKSIZE_IRQ;
 #endif
 	return 0;