diff --git a/src/expr.rs b/src/expr.rs
index 5640e4d..206577c 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -2,6 +2,7 @@ use serde::{Deserialize, Serialize};
 use std::collections::HashSet;
 
 use crate::stmt::Statement;
+use crate::stmt::Counter;
 
 #[derive(Debug, Clone, Eq, PartialEq, Serialize, Deserialize)]
 #[serde(untagged)]
@@ -355,9 +356,10 @@ pub enum Verdict {
 /// Explicitly set element object.
 pub struct Elem {
     pub val: Box<Expression>,
-    pub timeout: u32,
-    pub expires: u32,
-    pub comment: String,
+    pub timeout: Option<u32>,
+    pub expires: Option<u32>,
+    pub comment: Option<String>,
+    pub counter: Option<Counter>,
 }
 
 #[derive(Debug, Clone, Eq, PartialEq, Serialize, Deserialize)]
diff --git a/src/schema.rs b/src/schema.rs
index 0bfe949..88daed4 100644
--- a/src/schema.rs
+++ b/src/schema.rs
@@ -193,6 +193,8 @@ pub struct Set {
     pub gc_interval: Option<u32>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub size: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub comment: Option<String>,
 }
 
 #[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
@@ -232,6 +234,9 @@ pub enum SetType {
     #[serde(rename = "mark")]
     #[strum(serialize="mark")]
     Mark,
+    #[serde(rename = "ifname")]
+    #[strum(serialize="ifname")]
+    Ifname,
 }
 
 #[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
@@ -249,6 +254,7 @@ pub enum SetFlag {
     Constant,
     Interval,
     Timeout,
+    Dynamic,
 }
 
 #[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
diff --git a/tests/helper_tests.rs b/tests/helper_tests.rs
index 2cb8af8..9576308 100644
--- a/tests/helper_tests.rs
+++ b/tests/helper_tests.rs
@@ -57,6 +57,7 @@ fn example_ruleset() -> schema::Nftables {
         timeout: None,
         gc_interval: None,
         size: None,
+        comment: None,
     }));
     // add element to set
     batch.add(schema::NfListObject::Element(schema::Element {