diff --git a/Cargo.toml b/Cargo.toml
index 09aa8b6..b2ffec7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "alfis"
-version = "0.4.33"
+version = "0.4.34"
 authors = ["Revertron <alfis@revertron.com>"]
 edition = "2018"
 build = "build.rs"
diff --git a/src/blockchain/chain.rs b/src/blockchain/chain.rs
index b5500e3..34a89e9 100644
--- a/src/blockchain/chain.rs
+++ b/src/blockchain/chain.rs
@@ -675,6 +675,13 @@ impl Chain {
         }
     }
 
+    pub fn get_soa_serial(&self) -> u32 {
+        match &self.last_full_block {
+            None => { 0 }
+            Some(block) => { block.timestamp as u32 }
+        }
+    }
+
     pub fn next_allowed_full_block(&self) -> u64 {
         match self.last_full_block {
             None => { self.get_height() + 1 }
diff --git a/src/blockchain/filter.rs b/src/blockchain/filter.rs
index 264b257..0977c12 100644
--- a/src/blockchain/filter.rs
+++ b/src/blockchain/filter.rs
@@ -5,7 +5,6 @@ use crate::dns::protocol::{DnsPacket, QueryType, DnsRecord, DnsQuestion, ResultC
 #[allow(unused_imports)]
 use log::{trace, debug, info, warn, error};
 use crate::blockchain::transaction::DomainData;
-use chrono::Utc;
 
 pub struct BlockchainFilter {
     context: Arc<Mutex<Context>>
@@ -28,7 +27,8 @@ impl DnsFilter for BlockchainFilter {
         match parts.len() {
             1 => {
                 let mut packet = DnsPacket::new();
-                if self.get_zone_response(parts[0], &mut packet) {
+                let serial = self.context.lock().unwrap().chain.get_soa_serial();
+                if self.get_zone_response(parts[0], serial, &mut packet) {
                     return Some(packet);
                 }
                 return None;
@@ -55,7 +55,8 @@ impl DnsFilter for BlockchainFilter {
                     packet.questions.push(DnsQuestion::new(String::from(qname), qtype));
                     packet.header.rescode = ResultCode::NXDOMAIN;
                     packet.header.authoritative_answer = true;
-                    BlockchainFilter::add_soa_record(zone, &mut packet);
+                    let serial = self.context.lock().unwrap().chain.get_soa_serial();
+                    BlockchainFilter::add_soa_record(zone, serial, &mut packet);
                     //trace!("Returning packet: {:?}", &packet);
                     return Some(packet);
                 }
@@ -165,7 +166,8 @@ impl DnsFilter for BlockchainFilter {
                     packet.header.authoritative_answer = true;
                     packet.header.rescode = ResultCode::NOERROR;
                     packet.questions.push(DnsQuestion::new(String::from(qname), qtype));
-                    BlockchainFilter::add_soa_record(zone, &mut packet);
+                    let serial = self.context.lock().unwrap().chain.get_soa_serial();
+                    BlockchainFilter::add_soa_record(zone, serial, &mut packet);
                     //trace!("Returning packet: {:?}", &packet);
                     Some(packet)
                 }
@@ -177,12 +179,12 @@ impl DnsFilter for BlockchainFilter {
 }
 
 impl BlockchainFilter {
-    fn add_soa_record(zone: String, packet: &mut DnsPacket) {
+    fn add_soa_record(zone: String, serial: u32, packet: &mut DnsPacket) {
         packet.authorities.push(DnsRecord::SOA {
             domain: zone,
             m_name: String::from(NAME_SERVER),
             r_name: String::from(SERVER_ADMIN),
-            serial: Utc::now().timestamp() as u32,
+            serial,
             refresh: 3600,
             retry: 300,
             expire: 604800,
@@ -191,11 +193,16 @@ impl BlockchainFilter {
         });
     }
 
-    fn get_zone_response(&self, zone: &str, mut packet: &mut DnsPacket) -> bool {
+    fn get_zone_response(&self, zone: &str, serial: u32, mut packet: &mut DnsPacket) -> bool {
         let have_zone = self.context.lock().unwrap().chain.is_zone_in_blockchain(i64::MAX as u64, zone);
         if have_zone {
-            BlockchainFilter::add_soa_record(zone.to_owned(), &mut packet);
+            BlockchainFilter::add_soa_record(zone.to_owned(), serial, &mut packet);
         }
         have_zone
     }
 }
+
+#[cfg(test)]
+mod tests {
+    // TODO write tests for this filter
+}
diff --git a/src/dns/client.rs b/src/dns/client.rs
index 7e6414b..16f42ce 100644
--- a/src/dns/client.rs
+++ b/src/dns/client.rs
@@ -145,8 +145,7 @@ impl DnsNetworkClient {
 
         packet.questions.push(DnsQuestion::new(qname.to_string(), qtype));
 
-        // Create a return channel, and add a `PendingQuery` to the list of lookups
-        // in progress
+        // Create a return channel, and add a `PendingQuery` to the list of lookups in progress
         let (tx, rx) = channel();
         {
             let mut pending_queries = self.pending_queries.lock().map_err(|_| ClientError::PoisonedLock)?;