diff --git a/net/dcsctp/tx/outstanding_data.cc b/net/dcsctp/tx/outstanding_data.cc
index 30d83870e3..1e584064a6 100644
--- a/net/dcsctp/tx/outstanding_data.cc
+++ b/net/dcsctp/tx/outstanding_data.cc
@@ -97,11 +97,6 @@ bool OutstandingData::IsConsistent() const {
     }
   }
 
-  if (outstanding_data_.empty() &&
-      next_tsn_ != last_cumulative_tsn_ack_.next_value()) {
-    return false;
-  }
-
   return actual_outstanding_bytes == outstanding_bytes_ &&
          actual_outstanding_items == outstanding_items_ &&
          actual_combined_to_be_retransmitted == combined_to_be_retransmitted;
@@ -275,12 +270,11 @@ void OutstandingData::AbandonAllFor(const Item& item) {
     // skipped over). So create a new fragment, representing the end, that the
     // received will never see as it is abandoned immediately and used as cum
     // TSN in the sent FORWARD-TSN.
-    UnwrappedTSN tsn = next_tsn_;
-    next_tsn_.Increment();
     Data message_end(item.data().stream_id, item.data().ssn, item.data().mid,
                      item.data().fsn, item.data().ppid, std::vector<uint8_t>(),
                      Data::IsBeginning(false), Data::IsEnd(true),
                      item.data().is_unordered);
+    UnwrappedTSN tsn = next_tsn();
     Item& added_item =
         outstanding_data_
             .emplace(std::piecewise_construct, std::forward_as_tuple(tsn),
@@ -394,8 +388,8 @@ void OutstandingData::ExpireOutstandingChunks(Timestamp now) {
 }
 
 UnwrappedTSN OutstandingData::highest_outstanding_tsn() const {
-  return outstanding_data_.empty() ? last_cumulative_tsn_ack_
-                                   : outstanding_data_.rbegin()->first;
+  return UnwrappedTSN::AddTo(last_cumulative_tsn_ack_,
+                             outstanding_data_.size());
 }
 
 absl::optional<UnwrappedTSN> OutstandingData::Insert(
@@ -405,13 +399,11 @@ absl::optional<UnwrappedTSN> OutstandingData::Insert(
     MaxRetransmits max_retransmissions,
     Timestamp expires_at,
     LifecycleId lifecycle_id) {
-  UnwrappedTSN tsn = next_tsn_;
-  next_tsn_.Increment();
-
   // All chunks are always padded to be even divisible by 4.
   size_t chunk_size = GetSerializedChunkSize(data);
   outstanding_bytes_ += chunk_size;
   ++outstanding_items_;
+  UnwrappedTSN tsn = next_tsn();
   auto it = outstanding_data_
                 .emplace(std::piecewise_construct, std::forward_as_tuple(tsn),
                          std::forward_as_tuple(message_id, data.Clone(),
@@ -542,16 +534,12 @@ IForwardTsnChunk OutstandingData::CreateIForwardTsn() const {
                           std::move(skipped_streams));
 }
 
-void OutstandingData::ResetSequenceNumbers(UnwrappedTSN next_tsn,
-                                           UnwrappedTSN last_cumulative_tsn) {
+void OutstandingData::ResetSequenceNumbers(UnwrappedTSN last_cumulative_tsn) {
   RTC_DCHECK(outstanding_data_.empty());
-  RTC_DCHECK(next_tsn_ == last_cumulative_tsn_ack_.next_value());
-  RTC_DCHECK(next_tsn == last_cumulative_tsn.next_value());
-  next_tsn_ = next_tsn;
   last_cumulative_tsn_ack_ = last_cumulative_tsn;
 }
 
 void OutstandingData::BeginResetStreams() {
-  stream_reset_breakpoint_tsns_.insert(next_tsn_);
+  stream_reset_breakpoint_tsns_.insert(next_tsn());
 }
 }  // namespace dcsctp
diff --git a/net/dcsctp/tx/outstanding_data.h b/net/dcsctp/tx/outstanding_data.h
index 3cad8069c1..406f80bbc1 100644
--- a/net/dcsctp/tx/outstanding_data.h
+++ b/net/dcsctp/tx/outstanding_data.h
@@ -75,11 +75,9 @@ class OutstandingData {
 
   OutstandingData(
       size_t data_chunk_header_size,
-      UnwrappedTSN next_tsn,
       UnwrappedTSN last_cumulative_tsn_ack,
       std::function<bool(StreamID, OutgoingMessageId)> discard_from_send_queue)
       : data_chunk_header_size_(data_chunk_header_size),
-        next_tsn_(next_tsn),
         last_cumulative_tsn_ack_(last_cumulative_tsn_ack),
         discard_from_send_queue_(std::move(discard_from_send_queue)) {}
 
@@ -122,7 +120,9 @@ class OutstandingData {
     return last_cumulative_tsn_ack_;
   }
 
-  UnwrappedTSN next_tsn() const { return next_tsn_; }
+  UnwrappedTSN next_tsn() const {
+    return highest_outstanding_tsn().next_value();
+  }
 
   UnwrappedTSN highest_outstanding_tsn() const;
 
@@ -160,8 +160,7 @@ class OutstandingData {
   bool ShouldSendForwardTsn() const;
 
   // Sets the next TSN to be used. This is used in handover.
-  void ResetSequenceNumbers(UnwrappedTSN next_tsn,
-                            UnwrappedTSN last_cumulative_tsn);
+  void ResetSequenceNumbers(UnwrappedTSN last_cumulative_tsn);
 
   // Called when an outgoing stream reset is sent, marking the last assigned TSN
   // as a breakpoint that a FORWARD-TSN shouldn't cross.
@@ -342,8 +341,6 @@ class OutstandingData {
 
   // The size of the data chunk (DATA/I-DATA) header that is used.
   const size_t data_chunk_header_size_;
-  // Next TSN to used.
-  UnwrappedTSN next_tsn_;
   // The last cumulative TSN ack number.
   UnwrappedTSN last_cumulative_tsn_ack_;
   // Callback when to discard items from the send queue.
diff --git a/net/dcsctp/tx/outstanding_data_test.cc b/net/dcsctp/tx/outstanding_data_test.cc
index 33fc51acf1..8bff4d4476 100644
--- a/net/dcsctp/tx/outstanding_data_test.cc
+++ b/net/dcsctp/tx/outstanding_data_test.cc
@@ -48,7 +48,6 @@ class OutstandingDataTest : public testing::Test {
   OutstandingDataTest()
       : gen_(MID(42)),
         buf_(DataChunk::kHeaderSize,
-             unwrapper_.Unwrap(TSN(10)),
              unwrapper_.Unwrap(TSN(9)),
              on_discard_.AsStdFunction()) {}
 
diff --git a/net/dcsctp/tx/retransmission_queue.cc b/net/dcsctp/tx/retransmission_queue.cc
index cd1cc14b4f..adff294a5f 100644
--- a/net/dcsctp/tx/retransmission_queue.cc
+++ b/net/dcsctp/tx/retransmission_queue.cc
@@ -86,7 +86,6 @@ RetransmissionQueue::RetransmissionQueue(
       send_queue_(send_queue),
       outstanding_data_(
           data_chunk_header_size_,
-          tsn_unwrapper_.Unwrap(my_initial_tsn),
           tsn_unwrapper_.Unwrap(TSN(*my_initial_tsn - 1)),
           [this](StreamID stream_id, OutgoingMessageId message_id) {
             return send_queue_.Discard(stream_id, message_id);
@@ -621,7 +620,6 @@ void RetransmissionQueue::RestoreFromState(
   partial_bytes_acked_ = state.tx.partial_bytes_acked;
 
   outstanding_data_.ResetSequenceNumbers(
-      tsn_unwrapper_.Unwrap(TSN(state.tx.next_tsn)),
       tsn_unwrapper_.Unwrap(TSN(state.tx.next_tsn - 1)));
 }
 }  // namespace dcsctp