diff --git a/parsers/src/muc/muc.rs b/parsers/src/muc/muc.rs
index 68c713f029de16f919f8326386b46ba9af51c106..d8b656399b03f3e26cd26c0d136df1e33f70f898 100644
--- a/parsers/src/muc/muc.rs
+++ b/parsers/src/muc/muc.rs
@@ -104,6 +104,20 @@ mod tests {
     use minidom::Element;
     use xso::error::{Error, FromElementError};
 
+    #[cfg(target_pointer_width = "32")]
+    #[test]
+    fn test_size() {
+        assert_size!(History, 40);
+        assert_size!(Muc, 52);
+    }
+
+    #[cfg(target_pointer_width = "64")]
+    #[test]
+    fn test_size() {
+        assert_size!(History, 40);
+        assert_size!(Muc, 64);
+    }
+
     #[test]
     fn test_muc_simple() {
         let elem: Element = "<x xmlns='http://jabber.org/protocol/muc'/>"
diff --git a/parsers/src/muc/user.rs b/parsers/src/muc/user.rs
index 82afd536f1855327ac1c271c75939b95ebc55abd..4f15a7a9a8441791d957abb87a74a0aea9a8b8f3 100644
--- a/parsers/src/muc/user.rs
+++ b/parsers/src/muc/user.rs
@@ -346,6 +346,36 @@ mod tests {
     use minidom::Element;
     use xso::error::{Error, FromElementError};
 
+    #[cfg(target_pointer_width = "32")]
+    #[test]
+    fn test_size() {
+        assert_size!(Status, 1);
+        assert_size!(Actor, 28);
+        assert_size!(Continue, 12);
+        assert_size!(Reason, 12);
+        assert_size!(Affiliation, 1);
+        assert_size!(Role, 1);
+        assert_size!(Item, 84);
+        assert_size!(Invite, 44);
+        assert_size!(Decline, 44);
+        assert_size!(MucUser, 112);
+    }
+
+    #[cfg(target_pointer_width = "64")]
+    #[test]
+    fn test_size() {
+        assert_size!(Status, 1);
+        assert_size!(Actor, 56);
+        assert_size!(Continue, 24);
+        assert_size!(Reason, 24);
+        assert_size!(Affiliation, 1);
+        assert_size!(Role, 1);
+        assert_size!(Item, 168);
+        assert_size!(Invite, 88);
+        assert_size!(Decline, 88);
+        assert_size!(MucUser, 224);
+    }
+
     #[test]
     fn test_simple() {
         let elem: Element = "<x xmlns='http://jabber.org/protocol/muc#user'/>"