diff --git a/sys/net/network_layer/sixlowpan/lowpan.c b/sys/net/network_layer/sixlowpan/lowpan.c
index 2e08efbaf6..085bab5665 100644
--- a/sys/net/network_layer/sixlowpan/lowpan.c
+++ b/sys/net/network_layer/sixlowpan/lowpan.c
@@ -1353,7 +1353,7 @@ void lowpan_iphc_decoding(uint8_t *data, uint8_t length, net_if_eui64_t *s_addr,
             case (0x03): {
                 /* 0-bits */
                 memcpy(&(ipv6_buf->srcaddr.uint8[0]), &ll_prefix[0], 2);
-                memset(&(ipv6_buf->srcaddr.uint8[2]), 0, 20);
+                memset(&(ipv6_buf->srcaddr.uint8[2]), 0, 6);
                 memcpy(&(ipv6_buf->srcaddr.uint8[8]), &s_addr->uint8[0], 8);
                 break;
             }