diff --git a/postgres_ffi/src/xlog_utils.rs b/postgres_ffi/src/xlog_utils.rs
index aabbf8628b..127e8afbf3 100644
--- a/postgres_ffi/src/xlog_utils.rs
+++ b/postgres_ffi/src/xlog_utils.rs
@@ -38,7 +38,7 @@ pub const XLOG_SIZE_OF_XLOG_RECORD: usize = std::mem::size_of::<XLogRecord>();
 
 pub type XLogRecPtr = u64;
 pub type TimeLineID = u32;
-pub type TimestampTz = u64;
+pub type TimestampTz = i64;
 pub type XLogSegNo = u64;
 
 #[allow(non_snake_case)]
@@ -90,9 +90,9 @@ pub fn get_current_timestamp() -> TimestampTz {
     const USECS_PER_SEC: u64 = 1000000;
     match SystemTime::now().duration_since(SystemTime::UNIX_EPOCH) {
         Ok(n) => {
-            (n.as_secs() - ((POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY))
-                * USECS_PER_SEC
-                + n.subsec_micros() as u64
+            ((n.as_secs() - ((POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY))
+             * USECS_PER_SEC
+             + n.subsec_micros() as u64) as i64
         }
         Err(_) => panic!("SystemTime before UNIX EPOCH!"),
     }
diff --git a/zenith_utils/src/pq_proto.rs b/zenith_utils/src/pq_proto.rs
index 77d73d50da..5570e1b223 100644
--- a/zenith_utils/src/pq_proto.rs
+++ b/zenith_utils/src/pq_proto.rs
@@ -360,7 +360,7 @@ impl Default for RowDescriptor<'_> {
 pub struct XLogDataBody<'a> {
     pub wal_start: u64,
     pub wal_end: u64,
-    pub timestamp: u64,
+    pub timestamp: i64,
     pub data: &'a [u8],
 }
 
@@ -626,7 +626,7 @@ impl<'a> BeMessage<'a> {
                     buf.put_u8(b'w');
                     buf.put_u64(body.wal_start);
                     buf.put_u64(body.wal_end);
-                    buf.put_u64(body.timestamp);
+                    buf.put_i64(body.timestamp);
                     buf.put_slice(body.data);
                     Ok::<_, io::Error>(())
                 })