diff --git a/src/message_handler.rs b/src/message_handler.rs
index 0728d7a..9a5378e 100644
--- a/src/message_handler.rs
+++ b/src/message_handler.rs
@@ -43,53 +43,9 @@ impl MessageHandler {
             .unwrap_or("Unknown")
     }
 
-    pub fn msh_serial_msg(&mut self, payload: &[u8]) -> PyResult<Vec<SiPunch>> {
-        let service_envelope =
-            ServiceEnvelope::decode(payload).map_err(|e| std::io::Error::from(e))?;
-        let packet = service_envelope
-            .packet
-            .ok_or(PyValueError::new_err("Missing packet in ServiceEnvelope"))?;
-        let mac_addr = format!("{:8x}", packet.from);
-        const SERIAL_APP: i32 = PortNum::SerialApp as i32;
-        let now = Local::now().fixed_offset();
-        let host_info = HostInfo {
-            name: self.resolve(&mac_addr).to_owned(),
-            mac_address: mac_addr.clone(),
-        };
-        let punches = match packet.payload_variant {
-            Some(PayloadVariant::Decoded(Data {
-                portnum: SERIAL_APP,
-                payload,
-                ..
-            })) => Ok(SiPunch::punches_from_payload(&payload[..], &host_info, now)),
-            _ => Err(std::io::Error::new(
-                std::io::ErrorKind::InvalidData,
-                format!("{}: Encrypted message or wrong portnum", host_info.name),
-            )),
-        }?;
-
-        let mut result = Vec::with_capacity(punches.len());
-        let status = self
-            .meshtastic_statuses
-            .entry(mac_addr)
-            .or_insert(MeshtasticRocStatus::new(host_info.name.clone()));
-        for punch in punches.into_iter() {
-            match punch {
-                Ok(punch) => {
-                    let mut punch = punch.clone();
-                    status.punch(&punch);
-                    if let Some(mac_addr) = self.meshtastic_override_mac.as_ref() {
-                        punch.host_info.mac_address = mac_addr.clone();
-                    }
-                    result.push(punch);
-                }
-                Err(err) => {
-                    error!("{}", err);
-                }
-            }
-        }
-
-        Ok(result)
+    #[pyo3(name = "meshtastic_serial_msg")]
+    pub fn msh_serial_msg_py(&mut self, payload: &[u8]) -> PyResult<Vec<SiPunch>> {
+        Ok(self.msh_serial_msg(payload)?)
     }
 
     pub fn msh_status_update(
@@ -202,6 +158,56 @@ impl MessageHandler {
         Ok(result)
     }
 
+    fn msh_serial_msg(&mut self, payload: &[u8]) -> std::io::Result<Vec<SiPunch>> {
+        let service_envelope =
+            ServiceEnvelope::decode(payload).map_err(|e| std::io::Error::from(e))?;
+        let packet = service_envelope.packet.ok_or(std::io::Error::new(
+            std::io::ErrorKind::InvalidInput,
+            "Missing packet in ServiceEnvelope",
+        ))?;
+        let mac_addr = format!("{:8x}", packet.from);
+        const SERIAL_APP: i32 = PortNum::SerialApp as i32;
+        let now = Local::now().fixed_offset();
+        let host_info = HostInfo {
+            name: self.resolve(&mac_addr).to_owned(),
+            mac_address: mac_addr.clone(),
+        };
+        let punches = match packet.payload_variant {
+            Some(PayloadVariant::Decoded(Data {
+                portnum: SERIAL_APP,
+                payload,
+                ..
+            })) => Ok(SiPunch::punches_from_payload(&payload[..], &host_info, now)),
+            _ => Err(std::io::Error::new(
+                std::io::ErrorKind::InvalidData,
+                format!("{}: Encrypted message or wrong portnum", host_info.name),
+            )),
+        }?;
+
+        let mut result = Vec::with_capacity(punches.len());
+        let status = self
+            .meshtastic_statuses
+            .entry(mac_addr)
+            .or_insert(MeshtasticRocStatus::new(host_info.name.clone()));
+        for punch in punches.into_iter() {
+            match punch {
+                Ok(punch) => {
+                    let mut punch = punch.clone();
+                    status.punch(&punch);
+                    if let Some(mac_addr) = self.meshtastic_override_mac.as_ref() {
+                        punch.host_info.mac_address = mac_addr.clone();
+                    }
+                    result.push(punch);
+                }
+                Err(err) => {
+                    error!("{}", err);
+                }
+            }
+        }
+
+        Ok(result)
+    }
+
     fn construct_punch(
         payload: &[u8],
         host_info: &HostInfo,
@@ -241,6 +247,8 @@ mod test_punch {
     use std::collections::HashMap;
 
     use chrono::DateTime;
+    use meshtastic::protobufs::{Data, MeshPacket, PortNum, ServiceEnvelope};
+    use meshtastic::Message as MeshtasticMessage;
     use prost::Message;
 
     use crate::{
@@ -283,4 +291,34 @@ mod test_punch {
         assert_eq!(punches[0].code, 47);
         assert_eq!(punches[0].card, 1715004);
     }
+
+    #[test]
+    fn test_meshtastic_serial() {
+        let time = DateTime::parse_from_rfc3339("2023-11-23T10:00:03.793+00:00").unwrap();
+        let punch = SiPunch::punch_to_bytes(47, time, 1715004, 2);
+
+        const SERIAL_APP: i32 = PortNum::SerialApp as i32;
+        let envelope = ServiceEnvelope {
+            packet: Some(MeshPacket {
+                to: 0xabcd,
+                from: 0x1234,
+                payload_variant: Some(meshtastic::protobufs::mesh_packet::PayloadVariant::Decoded(
+                    Data {
+                        portnum: SERIAL_APP,
+                        payload: punch.to_vec(),
+                        ..Default::default()
+                    },
+                )),
+                ..Default::default()
+            }),
+            ..Default::default()
+        };
+
+        let message = envelope.encode_to_vec();
+        let mut handler = MessageHandler::new(HashMap::new(), None);
+        let punches = handler.msh_serial_msg(&message[..]).unwrap();
+        assert_eq!(punches.len(), 1);
+        assert_eq!(punches[0].code, 47);
+        assert_eq!(punches[0].card, 1715004);
+    }
 }