diff --git a/cbor_gen.go b/cbor_gen.go
index e13bcf43a..f83d35990 100644
--- a/cbor_gen.go
+++ b/cbor_gen.go
@@ -980,7 +980,7 @@ func (t *Log) MarshalCBOR(w io.Writer) error {
 		_, err := w.Write(cbg.CborNull)
 		return err
 	}
-	if _, err := w.Write([]byte{165}); err != nil {
+	if _, err := w.Write([]byte{164}); err != nil {
 		return err
 	}
 
@@ -1068,29 +1068,6 @@ func (t *Log) MarshalCBOR(w io.Writer) error {
 	if _, err := w.Write([]byte(t.Kind)); err != nil {
 		return err
 	}
-
-	// t.Params ([]uint8) (slice)
-	if len("Params") > cbg.MaxLength {
-		return xerrors.Errorf("Value in field \"Params\" was too long")
-	}
-
-	if _, err := w.Write(cbg.CborEncodeMajorType(cbg.MajTextString, uint64(len("Params")))); err != nil {
-		return err
-	}
-	if _, err := w.Write([]byte("Params")); err != nil {
-		return err
-	}
-
-	if len(t.Params) > cbg.ByteArrayMaxLen {
-		return xerrors.Errorf("Byte array in field t.Params was too long")
-	}
-
-	if _, err := w.Write(cbg.CborEncodeMajorType(cbg.MajByteString, uint64(len(t.Params)))); err != nil {
-		return err
-	}
-	if _, err := w.Write(t.Params); err != nil {
-		return err
-	}
 	return nil
 }
 
@@ -1168,24 +1145,6 @@ func (t *Log) UnmarshalCBOR(r io.Reader) error {
 
 				t.Kind = string(sval)
 			}
-			// t.Params ([]uint8) (slice)
-		case "Params":
-
-			maj, extra, err = cbg.CborReadHeader(br)
-			if err != nil {
-				return err
-			}
-
-			if extra > cbg.ByteArrayMaxLen {
-				return fmt.Errorf("t.Params: byte array too large (%d)", extra)
-			}
-			if maj != cbg.MajByteString {
-				return fmt.Errorf("expected byte array")
-			}
-			t.Params = make([]byte, extra)
-			if _, err := io.ReadFull(br, t.Params); err != nil {
-				return err
-			}
 
 		default:
 			return fmt.Errorf("unknown struct field %d: '%s'", i, name)
diff --git a/fsm.go b/fsm.go
index ba2702696..fced052aa 100644
--- a/fsm.go
+++ b/fsm.go
@@ -2,7 +2,9 @@ package sealing
 
 import (
 	"context"
+	"fmt"
 	"reflect"
+	"time"
 
 	"golang.org/x/xerrors"
 
@@ -66,6 +68,20 @@ func (m *Sealing) plan(events []statemachine.Event, state *SectorInfo) (func(sta
 	/////
 	// First process all events
 
+	for _, event := range events {
+		l := Log{
+			Timestamp: uint64(time.Now().Unix()),
+			Message:   fmt.Sprintf("%+v", event),
+			Kind:      fmt.Sprintf("event;%T", event.User),
+		}
+
+		if err, iserr := event.User.(xerrors.Formatter); iserr {
+			l.Trace = fmt.Sprintf("%+v", err)
+		}
+
+		state.Log = append(state.Log, l)
+	}
+
 	p := fsmPlanners[state.State]
 	if p == nil {
 		return nil, xerrors.Errorf("planner for state %d not found", state.State)
diff --git a/types.go b/types.go
index ae8d7ac23..952c5ec22 100644
--- a/types.go
+++ b/types.go
@@ -53,7 +53,6 @@ type Log struct {
 
 	// additional data (Event info)
 	Kind   string
-	Params []byte
 }
 
 type SectorInfo struct {