diff --git a/go.mod b/go.mod
index e788f43d..eddf96a7 100644
--- a/go.mod
+++ b/go.mod
@@ -22,7 +22,7 @@ require (
 	github.com/matrix-org/go-http-js-libp2p v0.0.0-20200518170932-783164aeeda4
 	github.com/matrix-org/go-sqlite3-js v0.0.0-20200522092705-bc8506ccbcf3
 	github.com/matrix-org/gomatrix v0.0.0-20200827122206-7dd5e2a05bcd
-	github.com/matrix-org/gomatrixserverlib v0.0.0-20201207162041-232bace0cdd4
+	github.com/matrix-org/gomatrixserverlib v0.0.0-20201209172200-eb6a8903f9fb
 	github.com/matrix-org/naffka v0.0.0-20200901083833-bcdd62999a91
 	github.com/matrix-org/util v0.0.0-20200807132607-55161520e1d4
 	github.com/mattn/go-sqlite3 v1.14.2
diff --git a/go.sum b/go.sum
index f00f06d6..fc48085a 100644
--- a/go.sum
+++ b/go.sum
@@ -567,8 +567,8 @@ github.com/matrix-org/gomatrix v0.0.0-20190528120928-7df988a63f26 h1:Hr3zjRsq2bh
 github.com/matrix-org/gomatrix v0.0.0-20190528120928-7df988a63f26/go.mod h1:3fxX6gUjWyI/2Bt7J1OLhpCzOfO/bB3AiX0cJtEKud0=
 github.com/matrix-org/gomatrix v0.0.0-20200827122206-7dd5e2a05bcd h1:xVrqJK3xHREMNjwjljkAUaadalWc0rRbmVuQatzmgwg=
 github.com/matrix-org/gomatrix v0.0.0-20200827122206-7dd5e2a05bcd/go.mod h1:/gBX06Kw0exX1HrwmoBibFA98yBk/jxKpGVeyQbff+s=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20201207162041-232bace0cdd4 h1:geIU3lUL+P83W6NdQLUaR7vfVh5EHliIJ0H/RgCqbIU=
-github.com/matrix-org/gomatrixserverlib v0.0.0-20201207162041-232bace0cdd4/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20201209172200-eb6a8903f9fb h1:UlhiSebJupQ+qAM93cdVGg4nAJ6bnxwAA5/EBygtYoo=
+github.com/matrix-org/gomatrixserverlib v0.0.0-20201209172200-eb6a8903f9fb/go.mod h1:JsAzE1Ll3+gDWS9JSUHPJiiyAksvOOnGWF2nXdg4ZzU=
 github.com/matrix-org/naffka v0.0.0-20200901083833-bcdd62999a91 h1:HJ6U3S3ljJqNffYMcIeAncp5qT/i+ZMiJ2JC2F0aXP4=
 github.com/matrix-org/naffka v0.0.0-20200901083833-bcdd62999a91/go.mod h1:sjyPyRxKM5uw1nD2cJ6O2OxI6GOqyVBfNXqKjBZTBZE=
 github.com/matrix-org/util v0.0.0-20190711121626-527ce5ddefc7 h1:ntrLa/8xVzeSs8vHFHK25k0C+NV74sYMJnNSg5NoSRo=
diff --git a/syncapi/storage/postgres/current_room_state_table.go b/syncapi/storage/postgres/current_room_state_table.go
index 12327278..554163e5 100644
--- a/syncapi/storage/postgres/current_room_state_table.go
+++ b/syncapi/storage/postgres/current_room_state_table.go
@@ -76,7 +76,7 @@ const selectRoomIDsWithMembershipSQL = "" +
 	"SELECT DISTINCT room_id FROM syncapi_current_room_state WHERE type = 'm.room.member' AND state_key = $1 AND membership = $2"
 
 const selectCurrentStateSQL = "" +
-	"SELECT headered_event_json FROM syncapi_current_room_state WHERE room_id = $1" +
+	"SELECT event_id, headered_event_json FROM syncapi_current_room_state WHERE room_id = $1" +
 	" AND ( $2::text[] IS NULL OR     sender  = ANY($2)  )" +
 	" AND ( $3::text[] IS NULL OR NOT(sender  = ANY($3)) )" +
 	" AND ( $4::text[] IS NULL OR     type LIKE ANY($4)  )" +
@@ -92,10 +92,10 @@ const selectStateEventSQL = "" +
 
 const selectEventsWithEventIDsSQL = "" +
 	// TODO: The session_id and transaction_id blanks are here because otherwise
-	// the rowsToStreamEvents expects there to be exactly five columns. We need to
+	// the rowsToStreamEvents expects there to be exactly six columns. We need to
 	// figure out if these really need to be in the DB, and if so, we need a
 	// better permanent fix for this. - neilalexander, 2 Jan 2020
-	"SELECT added_at, headered_event_json, 0 AS session_id, false AS exclude_from_sync, '' AS transaction_id" +
+	"SELECT event_id, added_at, headered_event_json, 0 AS session_id, false AS exclude_from_sync, '' AS transaction_id" +
 	" FROM syncapi_current_room_state WHERE event_id = ANY($1)"
 
 type currentRoomStateStatements struct {
@@ -278,13 +278,14 @@ func (s *currentRoomStateStatements) SelectEventsWithEventIDs(
 func rowsToEvents(rows *sql.Rows) ([]*gomatrixserverlib.HeaderedEvent, error) {
 	result := []*gomatrixserverlib.HeaderedEvent{}
 	for rows.Next() {
+		var eventID string
 		var eventBytes []byte
-		if err := rows.Scan(&eventBytes); err != nil {
+		if err := rows.Scan(&eventID, &eventBytes); err != nil {
 			return nil, err
 		}
 		// TODO: Handle redacted events
 		var ev gomatrixserverlib.HeaderedEvent
-		if err := json.Unmarshal(eventBytes, &ev); err != nil {
+		if err := ev.UnmarshalJSONWithEventID(eventBytes, eventID); err != nil {
 			return nil, err
 		}
 		result = append(result, &ev)
diff --git a/syncapi/storage/postgres/output_room_events_table.go b/syncapi/storage/postgres/output_room_events_table.go
index ce4b6335..f4bbebd2 100644
--- a/syncapi/storage/postgres/output_room_events_table.go
+++ b/syncapi/storage/postgres/output_room_events_table.go
@@ -79,20 +79,20 @@ const insertEventSQL = "" +
 	"RETURNING id"
 
 const selectEventsSQL = "" +
-	"SELECT id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events WHERE event_id = ANY($1)"
+	"SELECT event_id, id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events WHERE event_id = ANY($1)"
 
 const selectRecentEventsSQL = "" +
-	"SELECT id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events" +
+	"SELECT event_id, id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events" +
 	" WHERE room_id = $1 AND id > $2 AND id <= $3" +
 	" ORDER BY id DESC LIMIT $4"
 
 const selectRecentEventsForSyncSQL = "" +
-	"SELECT id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events" +
+	"SELECT event_id, id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events" +
 	" WHERE room_id = $1 AND id > $2 AND id <= $3 AND exclude_from_sync = FALSE" +
 	" ORDER BY id DESC LIMIT $4"
 
 const selectEarlyEventsSQL = "" +
-	"SELECT id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events" +
+	"SELECT event_id, id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events" +
 	" WHERE room_id = $1 AND id > $2 AND id <= $3" +
 	" ORDER BY id ASC LIMIT $4"
 
@@ -413,6 +413,7 @@ func rowsToStreamEvents(rows *sql.Rows) ([]types.StreamEvent, error) {
 	var result []types.StreamEvent
 	for rows.Next() {
 		var (
+			eventID         string
 			streamPos       types.StreamPosition
 			eventBytes      []byte
 			excludeFromSync bool
@@ -420,12 +421,12 @@ func rowsToStreamEvents(rows *sql.Rows) ([]types.StreamEvent, error) {
 			txnID           *string
 			transactionID   *api.TransactionID
 		)
-		if err := rows.Scan(&streamPos, &eventBytes, &sessionID, &excludeFromSync, &txnID); err != nil {
+		if err := rows.Scan(&eventID, &streamPos, &eventBytes, &sessionID, &excludeFromSync, &txnID); err != nil {
 			return nil, err
 		}
 		// TODO: Handle redacted events
 		var ev gomatrixserverlib.HeaderedEvent
-		if err := json.Unmarshal(eventBytes, &ev); err != nil {
+		if err := ev.UnmarshalJSONWithEventID(eventBytes, eventID); err != nil {
 			return nil, err
 		}
 
diff --git a/syncapi/storage/shared/syncserver.go b/syncapi/storage/shared/syncserver.go
index 6c35a765..9df04943 100644
--- a/syncapi/storage/shared/syncserver.go
+++ b/syncapi/storage/shared/syncserver.go
@@ -31,6 +31,7 @@ import (
 	"github.com/matrix-org/dendrite/syncapi/storage/tables"
 	"github.com/matrix-org/dendrite/syncapi/types"
 	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -514,25 +515,28 @@ func (d *Database) addPDUDeltaToResponse(
 		deltas, joinedRoomIDs, err = d.getStateDeltas(
 			ctx, &device, txn, r, device.UserID, &stateFilter,
 		)
+		if err != nil {
+			return nil, fmt.Errorf("d.getStateDeltas: %w", err)
+		}
 	} else {
 		deltas, joinedRoomIDs, err = d.getStateDeltasForFullStateSync(
 			ctx, &device, txn, r, device.UserID, &stateFilter,
 		)
-	}
-	if err != nil {
-		return nil, err
+		if err != nil {
+			return nil, fmt.Errorf("d.getStateDeltasForFullStateSync: %w", err)
+		}
 	}
 
 	for _, delta := range deltas {
 		err = d.addRoomDeltaToResponse(ctx, &device, txn, r, delta, numRecentEventsPerRoom, res)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("d.addRoomDeltaToResponse: %w", err)
 		}
 	}
 
 	// TODO: This should be done in getStateDeltas
 	if err = d.addInvitesToResponse(ctx, txn, device.UserID, r, res); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("d.addInvitesToResponse: %w", err)
 	}
 
 	succeeded = true
@@ -1126,7 +1130,13 @@ func (d *Database) fetchMissingStateEvents(
 		return nil, err
 	}
 	if len(stateEvents) != len(missing) {
-		return nil, fmt.Errorf("failed to map all event IDs to events: (got %d, wanted %d)", len(stateEvents), len(missing))
+		logrus.WithContext(ctx).Warnf("Failed to map all event IDs to events (got %d, wanted %d)", len(stateEvents), len(missing))
+
+		// TODO: Why is this happening? It's probably the roomserver. Uncomment
+		// this error again when we work out what it is and fix it, otherwise we
+		// just end up returning lots of 500s to the client and that breaks
+		// pretty much everything, rather than just sending what we have.
+		//return nil, fmt.Errorf("failed to map all event IDs to events: (got %d, wanted %d)", len(stateEvents), len(missing))
 	}
 	events = append(events, stateEvents...)
 	return events, nil
diff --git a/syncapi/storage/sqlite3/current_room_state_table.go b/syncapi/storage/sqlite3/current_room_state_table.go
index 357d4282..f16a6612 100644
--- a/syncapi/storage/sqlite3/current_room_state_table.go
+++ b/syncapi/storage/sqlite3/current_room_state_table.go
@@ -64,7 +64,7 @@ const selectRoomIDsWithMembershipSQL = "" +
 	"SELECT DISTINCT room_id FROM syncapi_current_room_state WHERE type = 'm.room.member' AND state_key = $1 AND membership = $2"
 
 const selectCurrentStateSQL = "" +
-	"SELECT headered_event_json FROM syncapi_current_room_state WHERE room_id = $1" +
+	"SELECT event_id, headered_event_json FROM syncapi_current_room_state WHERE room_id = $1" +
 	" AND ( $2 IS NULL OR     sender IN ($2)  )" +
 	" AND ( $3 IS NULL OR NOT(sender IN ($3)) )" +
 	" AND ( $4 IS NULL OR     type   IN ($4)  )" +
@@ -80,10 +80,10 @@ const selectStateEventSQL = "" +
 
 const selectEventsWithEventIDsSQL = "" +
 	// TODO: The session_id and transaction_id blanks are here because otherwise
-	// the rowsToStreamEvents expects there to be exactly five columns. We need to
+	// the rowsToStreamEvents expects there to be exactly six columns. We need to
 	// figure out if these really need to be in the DB, and if so, we need a
 	// better permanent fix for this. - neilalexander, 2 Jan 2020
-	"SELECT added_at, headered_event_json, 0 AS session_id, false AS exclude_from_sync, '' AS transaction_id" +
+	"SELECT event_id, added_at, headered_event_json, 0 AS session_id, false AS exclude_from_sync, '' AS transaction_id" +
 	" FROM syncapi_current_room_state WHERE event_id IN ($1)"
 
 type currentRoomStateStatements struct {
@@ -289,13 +289,14 @@ func (s *currentRoomStateStatements) SelectEventsWithEventIDs(
 func rowsToEvents(rows *sql.Rows) ([]*gomatrixserverlib.HeaderedEvent, error) {
 	result := []*gomatrixserverlib.HeaderedEvent{}
 	for rows.Next() {
+		var eventID string
 		var eventBytes []byte
-		if err := rows.Scan(&eventBytes); err != nil {
+		if err := rows.Scan(&eventID, &eventBytes); err != nil {
 			return nil, err
 		}
 		// TODO: Handle redacted events
 		var ev gomatrixserverlib.HeaderedEvent
-		if err := json.Unmarshal(eventBytes, &ev); err != nil {
+		if err := ev.UnmarshalJSONWithEventID(eventBytes, eventID); err != nil {
 			return nil, err
 		}
 		result = append(result, &ev)
diff --git a/syncapi/storage/sqlite3/output_room_events_table.go b/syncapi/storage/sqlite3/output_room_events_table.go
index 06407582..edbd36fb 100644
--- a/syncapi/storage/sqlite3/output_room_events_table.go
+++ b/syncapi/storage/sqlite3/output_room_events_table.go
@@ -56,20 +56,20 @@ const insertEventSQL = "" +
 	"ON CONFLICT (event_id) DO UPDATE SET exclude_from_sync = $13"
 
 const selectEventsSQL = "" +
-	"SELECT id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events WHERE event_id = $1"
+	"SELECT event_id, id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events WHERE event_id = $1"
 
 const selectRecentEventsSQL = "" +
-	"SELECT id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events" +
+	"SELECT event_id, id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events" +
 	" WHERE room_id = $1 AND id > $2 AND id <= $3" +
 	" ORDER BY id DESC LIMIT $4"
 
 const selectRecentEventsForSyncSQL = "" +
-	"SELECT id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events" +
+	"SELECT event_id, id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events" +
 	" WHERE room_id = $1 AND id > $2 AND id <= $3 AND exclude_from_sync = FALSE" +
 	" ORDER BY id DESC LIMIT $4"
 
 const selectEarlyEventsSQL = "" +
-	"SELECT id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events" +
+	"SELECT event_id, id, headered_event_json, session_id, exclude_from_sync, transaction_id FROM syncapi_output_room_events" +
 	" WHERE room_id = $1 AND id > $2 AND id <= $3" +
 	" ORDER BY id ASC LIMIT $4"
 
@@ -428,6 +428,7 @@ func rowsToStreamEvents(rows *sql.Rows) ([]types.StreamEvent, error) {
 	var result []types.StreamEvent
 	for rows.Next() {
 		var (
+			eventID         string
 			streamPos       types.StreamPosition
 			eventBytes      []byte
 			excludeFromSync bool
@@ -435,12 +436,12 @@ func rowsToStreamEvents(rows *sql.Rows) ([]types.StreamEvent, error) {
 			txnID           *string
 			transactionID   *api.TransactionID
 		)
-		if err := rows.Scan(&streamPos, &eventBytes, &sessionID, &excludeFromSync, &txnID); err != nil {
+		if err := rows.Scan(&eventID, &streamPos, &eventBytes, &sessionID, &excludeFromSync, &txnID); err != nil {
 			return nil, err
 		}
 		// TODO: Handle redacted events
 		var ev gomatrixserverlib.HeaderedEvent
-		if err := json.Unmarshal(eventBytes, &ev); err != nil {
+		if err := ev.UnmarshalJSONWithEventID(eventBytes, eventID); err != nil {
 			return nil, err
 		}