diff --git a/xep-0359.xml b/xep-0359.xml
index 1f7cbb2e..256f7475 100644
--- a/xep-0359.xml
+++ b/xep-0359.xml
@@ -127,9 +127,9 @@
 	<li>XMPP entities, which are routing stanzas, MUST NOT strip any elements qualified by the 'urn:xmpp:sid:0' namespace from message stanzas. They SHOULD however ensure that those elements contain only the attributes defined herein, and take appropriate countermeasures if this is not the case (e.g. removing those attributes).</li>
 	<li>The values of the 'id' attribute SHOULD be unpredictable.</li>
 	<li>Stanza ID generating entities, which encounter a &stanza-id; element where 'id' is already set and where the 'by' attribute matches their own XMPP address, MUST ignore the existing value of 'id' and override it.</li>
-	<li>Stanzas MUST posses, in the direct child level of the stanza, at most one &stanza-id; extension element with the same XMPP address as value of the 'by' attribute.</li>
+	<li>Stanzas MUST possess, in the direct child level of the stanza, at most one &stanza-id; extension element with the same XMPP address as value of the 'by' attribute.</li>
 	<li>Every &stanza-id; extension element MUST have the 'id' attribute and the 'by' attribute set.</li>
-	<li>Every &stanza-id; and &origin-id; extension element MUST always posses an 'id' attribute and MUST NOT have any child elements or text content.</li>
+	<li>Every &stanza-id; and &origin-id; extension element MUST always possess an 'id' attribute and MUST NOT have any child elements or text content.</li>
 	<li>The value of the 'by' attribute MUST be the XMPP address of the entity assigning the unique and stable stanza ID. Note that XMPP addresses are normalized as defined in &rfc6122;</li>
   </ol>
 </section1>