diff --git a/doap.xml b/doap.xml
index f591bfff..3320bfa7 100644
--- a/doap.xml
+++ b/doap.xml
@@ -235,7 +235,7 @@
         <xmpp:SupportedXep>
             <xmpp:xep rdf:resource="https://xmpp.org/extensions/xep-0184.html"/>
             <xmpp:status>complete</xmpp:status>
-            <xmpp:version>1.3.0</xmpp:version>
+            <xmpp:version>1.4.0</xmpp:version>
             <xmpp:since>0.1.0</xmpp:since>
         </xmpp:SupportedXep>
     </implements>
diff --git a/src/avatar.rs b/src/avatar.rs
index e5c09d2a..0940c33a 100644
--- a/src/avatar.rs
+++ b/src/avatar.rs
@@ -58,6 +58,7 @@ impl PubSubPayload for Data {}
 mod tests {
     use super::*;
     use crate::hashes::Algo;
+    #[cfg(not(feature = "disable-validation"))]
     use crate::util::error::Error;
     use minidom::Element;
     use std::convert::TryFrom;
diff --git a/src/receipts.rs b/src/receipts.rs
index 3b54d3cd..af40f641 100644
--- a/src/receipts.rs
+++ b/src/receipts.rs
@@ -22,7 +22,7 @@ generate_element!(
     Received, "received", RECEIPTS,
     attributes: [
         /// The 'id' attribute of the received message.
-        id: Option<String> = "id",
+        id: Required<String> = "id",
     ]
 );
 
@@ -34,6 +34,7 @@ mod tests {
     use crate::ns;
     use minidom::Element;
     use std::convert::TryFrom;
+    use crate::util::error::Error;
 
     #[cfg(target_pointer_width = "32")]
     #[test]
@@ -54,15 +55,23 @@ mod tests {
         let elem: Element = "<request xmlns='urn:xmpp:receipts'/>".parse().unwrap();
         Request::try_from(elem).unwrap();
 
-        let elem: Element = "<received xmlns='urn:xmpp:receipts'/>".parse().unwrap();
-        Received::try_from(elem).unwrap();
-
         let elem: Element = "<received xmlns='urn:xmpp:receipts' id='coucou'/>"
             .parse()
             .unwrap();
         Received::try_from(elem).unwrap();
     }
 
+    #[test]
+    fn test_missing_id() {
+        let elem: Element = "<received xmlns='urn:xmpp:receipts'/>".parse().unwrap();
+        let error = Received::try_from(elem).unwrap_err();
+        let message = match error {
+            Error::ParseError(string) => string,
+            _ => panic!(),
+        };
+        assert_eq!(message, "Required attribute 'id' missing.");
+    }
+
     #[test]
     fn test_serialise() {
         let receipt = Request;
@@ -71,7 +80,7 @@ mod tests {
         assert_eq!(elem.attrs().count(), 0);
 
         let receipt = Received {
-            id: Some(String::from("coucou")),
+            id: String::from("coucou"),
         };
         let elem: Element = receipt.into();
         assert!(elem.is("received", ns::RECEIPTS));