diff --git a/arch/parisc/include/asm/checksum.h b/arch/parisc/include/asm/checksum.h
index 7861d365ba1e..ef34e8f839d5 100644
--- a/arch/parisc/include/asm/checksum.h
+++ b/arch/parisc/include/asm/checksum.h
@@ -141,6 +141,7 @@ static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 	** Try to keep 4 registers with "live" values ahead of the ALU.
 	*/
 
+"	depdi		0, 31, 32, %0\n"/* clear upper half of incoming checksum */
 "	ldd,ma		8(%1), %4\n"	/* get 1st saddr word */
 "	ldd,ma		8(%2), %5\n"	/* get 1st daddr word */
 "	add		%4, %0, %0\n"