diff --git a/types/mempool/priority_nonce.go b/types/mempool/priority_nonce.go
index 4d0735cfd8..abecfb1432 100644
--- a/types/mempool/priority_nonce.go
+++ b/types/mempool/priority_nonce.go
@@ -226,7 +226,7 @@ func (mp *PriorityNonceMempool[C]) Insert(ctx context.Context, tx sdk.Tx) error
 
 	// if it's an unordered tx, we use the timeout timestamp instead of the nonce
 	if unordered, ok := tx.(sdk.TxWithUnordered); ok && unordered.GetUnordered() {
-		timestamp := unordered.GetTimeoutTimeStamp().Unix()
+		timestamp := unordered.GetTimeoutTimeStamp().UnixNano()
 		if timestamp < 0 {
 			return errors.New("invalid timestamp value")
 		}
@@ -471,7 +471,7 @@ func (mp *PriorityNonceMempool[C]) Remove(tx sdk.Tx) error {
 
 	// if it's an unordered tx, we use the timeout timestamp instead of the nonce
 	if unordered, ok := tx.(sdk.TxWithUnordered); ok && unordered.GetUnordered() {
-		timestamp := unordered.GetTimeoutTimeStamp().Unix()
+		timestamp := unordered.GetTimeoutTimeStamp().UnixNano()
 		if timestamp < 0 {
 			return errors.New("invalid timestamp value")
 		}
diff --git a/types/mempool/sender_nonce.go b/types/mempool/sender_nonce.go
index 4d4d33e545..2623fefd95 100644
--- a/types/mempool/sender_nonce.go
+++ b/types/mempool/sender_nonce.go
@@ -143,7 +143,7 @@ func (snm *SenderNonceMempool) Insert(_ context.Context, tx sdk.Tx) error {
 
 	// if it's an unordered tx, we use the timeout timestamp instead of the nonce
 	if unordered, ok := tx.(sdk.TxWithUnordered); ok && unordered.GetUnordered() {
-		timestamp := unordered.GetTimeoutTimeStamp().Unix()
+		timestamp := unordered.GetTimeoutTimeStamp().UnixNano()
 		if timestamp < 0 {
 			return errors.New("invalid timestamp value")
 		}
@@ -240,7 +240,7 @@ func (snm *SenderNonceMempool) Remove(tx sdk.Tx) error {
 
 	// if it's an unordered tx, we use the timeout timestamp instead of the nonce
 	if unordered, ok := tx.(sdk.TxWithUnordered); ok && unordered.GetUnordered() {
-		timestamp := unordered.GetTimeoutTimeStamp().Unix()
+		timestamp := unordered.GetTimeoutTimeStamp().UnixNano()
 		if timestamp < 0 {
 			return errors.New("invalid timestamp value")
 		}
diff --git a/types/tx_msg.go b/types/tx_msg.go
index 6e014f8265..965554bee0 100644
--- a/types/tx_msg.go
+++ b/types/tx_msg.go
@@ -77,6 +77,8 @@ type (
 	TxWithTimeoutTimeStamp interface {
 		Tx
 
+		// GetTimeoutTimeStamp gets the timeout timestamp for the tx.
+		// IMPORTANT: when the uint value is needed here, you MUST use UnixNano.
 		GetTimeoutTimeStamp() time.Time
 	}