diff --git a/sys/mips/mips/locore.S b/sys/mips/mips/locore.S
index e45e2398b3cd..9f685ebfee4c 100644
--- a/sys/mips/mips/locore.S
+++ b/sys/mips/mips/locore.S
@@ -161,11 +161,11 @@ VECTOR(_locore, unknown)
 	/*
 	 * Initialize stack and call machine startup.
 	 */
-	PTR_LA	sp, _C_LABEL(pcpu_space)
-	addiu	sp, (PAGE_SIZE * 2) - CALLFRAME_SIZ
+	PTR_LA		sp, _C_LABEL(pcpu_space)
+	PTR_ADDU	sp, (PAGE_SIZE * 2) - CALLFRAME_SIZ
 
-	sw	zero, CALLFRAME_SIZ - 4(sp)	# Zero out old ra for debugger
-	sw	zero, CALLFRAME_SIZ - 8(sp)	# Zero out old fp for debugger
+	REG_S	zero, CALLFRAME_RA(sp)	# Zero out old ra for debugger
+	REG_S	zero, CALLFRAME_SP(sp)	# Zero out old fp for debugger
 
 	PTR_LA	gp, _C_LABEL(_gp)