diff --git a/src/runtime/sys_linux_ppc64x.s b/src/runtime/sys_linux_ppc64x.s
index de14418338..8629fe3233 100644
--- a/src/runtime/sys_linux_ppc64x.s
+++ b/src/runtime/sys_linux_ppc64x.s
@@ -280,7 +280,7 @@ fallback:
 	ADD	$32, R1, R4
 	SYSCALL $SYS_clock_gettime
 	MOVD	32(R1), R3
-	MOVD	48(R1), R5
+	MOVD	40(R1), R5
 	JMP	finish
 
 TEXT runtime·rtsigprocmask(SB),NOSPLIT|NOFRAME,$0-28