diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index 0a94e3ece7..ae0fa4d7cd 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -1360,7 +1360,7 @@ rte_pktmbuf_ext_shinfo_init_helper(void *buf_addr, uint16_t *buf_len,
 	shinfo->fcb_opaque = fcb_opaque;
 	rte_mbuf_ext_refcnt_set(shinfo, 1);
 
-	*buf_len = RTE_PTR_DIFF(shinfo, buf_addr);
+	*buf_len = (uint16_t)RTE_PTR_DIFF(shinfo, buf_addr);
 	return shinfo;
 }