diff --git a/crypto-msg-parser/src/exchanges/gate/gate_spot_current.rs b/crypto-msg-parser/src/exchanges/gate/gate_spot_current.rs
index 779d3831..d3612322 100644
--- a/crypto-msg-parser/src/exchanges/gate/gate_spot_current.rs
+++ b/crypto-msg-parser/src/exchanges/gate/gate_spot_current.rs
@@ -157,7 +157,7 @@ fn parse_l2_update(msg: &str) -> Result<Vec<OrderBookMsg>, SimpleError> {
         msg_type: MessageType::L2Event,
         timestamp: result.t,
         seq_id: Some(result.u as u64),
-        prev_seq_id: None,
+        prev_seq_id: Some(result.U as u64 - 1),
         asks: if let Some(asks) = result.a {
             asks.iter().map(parse_order).collect()
         } else {
diff --git a/crypto-msg-parser/src/exchanges/gate/gate_swap.rs b/crypto-msg-parser/src/exchanges/gate/gate_swap.rs
index 576edc11..0b3d07e5 100644
--- a/crypto-msg-parser/src/exchanges/gate/gate_swap.rs
+++ b/crypto-msg-parser/src/exchanges/gate/gate_swap.rs
@@ -414,7 +414,10 @@ fn parse_l2_update(market_type: MarketType, msg: &str) -> Result<Vec<OrderBookMs
         msg_type: MessageType::L2Event,
         timestamp: result.t,
         seq_id: result.extra.get("u").and_then(|v| v.as_u64()),
-        prev_seq_id: None,
+        prev_seq_id: result
+            .extra
+            .get("U")
+            .and_then(|v| v.as_u64().map(|v| v - 1)),
         asks: result
             .a
             .iter()