diff --git a/net/dcsctp/rx/traditional_reassembly_streams.cc b/net/dcsctp/rx/traditional_reassembly_streams.cc
index 4ccc2e5278..f5dc8cacc8 100644
--- a/net/dcsctp/rx/traditional_reassembly_streams.cc
+++ b/net/dcsctp/rx/traditional_reassembly_streams.cc
@@ -261,11 +261,11 @@ size_t TraditionalReassemblyStreams::OrderedStream::EraseTo(SSN ssn) {
 
 int TraditionalReassemblyStreams::Add(UnwrappedTSN tsn, Data data) {
   if (data.is_unordered) {
-    auto it = unordered_streams_.emplace(data.stream_id, this).first;
+    auto it = unordered_streams_.try_emplace(data.stream_id, this).first;
     return it->second.Add(tsn, std::move(data));
   }
 
-  auto it = ordered_streams_.emplace(data.stream_id, this).first;
+  auto it = ordered_streams_.try_emplace(data.stream_id, this).first;
   return it->second.Add(tsn, std::move(data));
 }
 
@@ -280,10 +280,9 @@ size_t TraditionalReassemblyStreams::HandleForwardTsn(
   }
 
   for (const auto& skipped_stream : skipped_streams) {
-    auto it = ordered_streams_.find(skipped_stream.stream_id);
-    if (it != ordered_streams_.end()) {
-      bytes_removed += it->second.EraseTo(skipped_stream.ssn);
-    }
+    auto it =
+        ordered_streams_.try_emplace(skipped_stream.stream_id, this).first;
+    bytes_removed += it->second.EraseTo(skipped_stream.ssn);
   }
 
   return bytes_removed;
diff --git a/net/dcsctp/rx/traditional_reassembly_streams_test.cc b/net/dcsctp/rx/traditional_reassembly_streams_test.cc
index 3e6f560aba..759962473d 100644
--- a/net/dcsctp/rx/traditional_reassembly_streams_test.cc
+++ b/net/dcsctp/rx/traditional_reassembly_streams_test.cc
@@ -25,8 +25,10 @@
 
 namespace dcsctp {
 namespace {
+using ::testing::ElementsAre;
 using ::testing::MockFunction;
 using ::testing::NiceMock;
+using ::testing::Property;
 
 class TraditionalReassemblyStreamsTest : public testing::Test {
  protected:
@@ -232,5 +234,24 @@ TEST_F(TraditionalReassemblyStreamsTest,
   EXPECT_EQ(streams2.Add(tsn(4), gen_.Unordered({7})), 1);
 }
 
+TEST_F(TraditionalReassemblyStreamsTest, CanDeleteFirstOrderedMessage) {
+  NiceMock<MockFunction<ReassemblyStreams::OnAssembledMessage>> on_assembled;
+  EXPECT_CALL(on_assembled,
+              Call(ElementsAre(tsn(2)),
+                   Property(&DcSctpMessage::payload, ElementsAre(2, 3, 4))));
+
+  TraditionalReassemblyStreams streams("", on_assembled.AsStdFunction());
+
+  // Not received, SID=1. TSN=1, SSN=0
+  gen_.Ordered({1}, "BE");
+  // And deleted (SID=1, TSN=1, SSN=0)
+  ForwardTsnChunk::SkippedStream skipped[] = {
+      ForwardTsnChunk::SkippedStream(StreamID(1), SSN(0))};
+  EXPECT_EQ(streams.HandleForwardTsn(tsn(1), skipped), 0u);
+
+  // Receive SID=1, TSN=2, SSN=1
+  EXPECT_EQ(streams.Add(tsn(2), gen_.Ordered({2, 3, 4}, "BE")), 0);
+}
+
 }  // namespace
 }  // namespace dcsctp
diff --git a/net/dcsctp/socket/dcsctp_socket_test.cc b/net/dcsctp/socket/dcsctp_socket_test.cc
index f45773baba..d30043d332 100644
--- a/net/dcsctp/socket/dcsctp_socket_test.cc
+++ b/net/dcsctp/socket/dcsctp_socket_test.cc
@@ -2179,5 +2179,40 @@ TEST(DcSctpSocketTest, BothCanDetectDcsctpImplementation) {
   EXPECT_EQ(a.socket.peer_implementation(), SctpImplementation::kDcsctp);
   EXPECT_EQ(z.socket.peer_implementation(), SctpImplementation::kDcsctp);
 }
+
+TEST_P(DcSctpSocketParametrizedTest, CanLoseFirstOrderedMessage) {
+  SocketUnderTest a("A");
+  auto z = std::make_unique<SocketUnderTest>("Z");
+
+  ConnectSockets(a, *z);
+  z = MaybeHandoverSocket(std::move(z));
+
+  SendOptions send_options;
+  send_options.unordered = IsUnordered(false);
+  send_options.max_retransmissions = 0;
+  std::vector<uint8_t> payload(a.options.mtu - 100);
+
+  // Send a first message (SID=1, SSN=0)
+  a.socket.Send(DcSctpMessage(StreamID(1), PPID(51), payload), send_options);
+
+  // First DATA is lost, and retransmission timer will delete it.
+  a.cb.ConsumeSentPacket();
+  AdvanceTime(a, *z, a.options.rto_initial);
+  ExchangeMessages(a, *z);
+
+  // Send a second message (SID=0, SSN=1).
+  a.socket.Send(DcSctpMessage(StreamID(1), PPID(52), payload), send_options);
+  ExchangeMessages(a, *z);
+
+  // The Z socket should receive the second message, but not the first.
+  absl::optional<DcSctpMessage> msg = z->cb.ConsumeReceivedMessage();
+  ASSERT_TRUE(msg.has_value());
+  EXPECT_EQ(msg->ppid(), PPID(52));
+
+  EXPECT_FALSE(z->cb.ConsumeReceivedMessage().has_value());
+
+  MaybeHandoverSocketAndSendMessage(a, std::move(z));
+}
+
 }  // namespace
 }  // namespace dcsctp