diff --git a/qlog/event.go b/qlog/event.go
index 71880ed58d1..1e91f3907d5 100644
--- a/qlog/event.go
+++ b/qlog/event.go
@@ -345,6 +345,8 @@ type eventTransportParameters struct {
 	InitialMaxStreamsUni           int64
 
 	PreferredAddress *preferredAddress
+
+	MaxDatagramFrameSize protocol.ByteCount
 }
 
 func (e eventTransportParameters) Category() category { return categoryTransport }
@@ -365,7 +367,7 @@ func (e eventTransportParameters) MarshalJSONObject(enc *gojay.Encoder) {
 	enc.StringKey("initial_source_connection_id", connectionID(e.InitialSourceConnectionID).String())
 	enc.BoolKey("disable_active_migration", e.DisableActiveMigration)
 	enc.FloatKeyOmitEmpty("max_idle_timeout", milliseconds(e.MaxIdleTimeout))
-	enc.Uint64KeyNullEmpty("max_udp_payload_size", uint64(e.MaxUDPPayloadSize))
+	enc.Int64KeyNullEmpty("max_udp_payload_size", int64(e.MaxUDPPayloadSize))
 	enc.Uint8KeyOmitEmpty("ack_delay_exponent", e.AckDelayExponent)
 	enc.FloatKeyOmitEmpty("max_ack_delay", milliseconds(e.MaxAckDelay))
 	enc.Uint64KeyOmitEmpty("active_connection_id_limit", e.ActiveConnectionIDLimit)
@@ -380,6 +382,9 @@ func (e eventTransportParameters) MarshalJSONObject(enc *gojay.Encoder) {
 	if e.PreferredAddress != nil {
 		enc.ObjectKey("preferred_address", e.PreferredAddress)
 	}
+	if e.MaxDatagramFrameSize != protocol.InvalidByteCount {
+		enc.Int64Key("max_datagram_frame_size", int64(e.MaxDatagramFrameSize))
+	}
 }
 
 type preferredAddress struct {
diff --git a/qlog/qlog.go b/qlog/qlog.go
index 5e38af48dd8..1e85ec15df6 100644
--- a/qlog/qlog.go
+++ b/qlog/qlog.go
@@ -205,6 +205,7 @@ func (t *connectionTracer) recordTransportParameters(sentBy protocol.Perspective
 		InitialMaxStreamsBidi:           int64(tp.MaxBidiStreamNum),
 		InitialMaxStreamsUni:            int64(tp.MaxUniStreamNum),
 		PreferredAddress:                pa,
+		MaxDatagramFrameSize:            tp.MaxDatagramFrameSize,
 	})
 	t.mutex.Unlock()
 }
diff --git a/qlog/qlog_test.go b/qlog/qlog_test.go
index 52b9eb7643c..2dd821b7bb1 100644
--- a/qlog/qlog_test.go
+++ b/qlog/qlog_test.go
@@ -244,6 +244,7 @@ var _ = Describe("Tracing", func() {
 					InitialSourceConnectionID:       protocol.ConnectionID{0xde, 0xad, 0xbe, 0xef},
 					RetrySourceConnectionID:         &protocol.ConnectionID{0xde, 0xca, 0xfb, 0xad},
 					ActiveConnectionIDLimit:         7,
+					MaxDatagramFrameSize:            protocol.InvalidByteCount,
 				})
 				entry := exportAndParseSingle()
 				Expect(entry.Time).To(BeTemporally("~", time.Now(), scaleDuration(10*time.Millisecond)))
@@ -265,6 +266,7 @@ var _ = Describe("Tracing", func() {
 				Expect(ev).To(HaveKeyWithValue("initial_max_streams_bidi", float64(10)))
 				Expect(ev).To(HaveKeyWithValue("initial_max_streams_uni", float64(20)))
 				Expect(ev).ToNot(HaveKey("preferred_address"))
+				Expect(ev).ToNot(HaveKey("max_datagram_frame_size"))
 			})
 
 			It("records the server's transport parameters, without a stateless reset token", func() {
@@ -317,6 +319,17 @@ var _ = Describe("Tracing", func() {
 				Expect(pa).To(HaveKeyWithValue("stateless_reset_token", "0f0e0d0c0b0a09080706050403020100"))
 			})
 
+			It("records transport parameters that enable the datagram extension", func() {
+				tracer.SentTransportParameters(&logging.TransportParameters{
+					MaxDatagramFrameSize: 1337,
+				})
+				entry := exportAndParseSingle()
+				Expect(entry.Time).To(BeTemporally("~", time.Now(), scaleDuration(10*time.Millisecond)))
+				Expect(entry.Name).To(Equal("transport:parameters_set"))
+				ev := entry.Event
+				Expect(ev).To(HaveKeyWithValue("max_datagram_frame_size", float64(1337)))
+			})
+
 			It("records received transport parameters", func() {
 				tracer.ReceivedTransportParameters(&logging.TransportParameters{})
 				entry := exportAndParseSingle()