diff --git a/conference.js b/conference.js
index f30cf0ff5..d5ac0a340 100644
--- a/conference.js
+++ b/conference.js
@@ -1804,9 +1804,9 @@ export default {
 
                 APP.UI.participantConnectionStatusChanged(id);
             });
-        room.on(JitsiConferenceEvents.DOMINANT_SPEAKER_CHANGED, id => {
-            APP.store.dispatch(dominantSpeakerChanged(id));
-        });
+        room.on(
+            JitsiConferenceEvents.DOMINANT_SPEAKER_CHANGED,
+            id => APP.store.dispatch(dominantSpeakerChanged(id, room)));
 
         if (!interfaceConfig.filmStripOnly) {
             room.on(JitsiConferenceEvents.CONNECTION_INTERRUPTED, () => {
@@ -1883,6 +1883,7 @@ export default {
                     = displayName.substr(0, MAX_DISPLAY_NAME_LENGTH);
 
                 APP.store.dispatch(participantUpdated({
+                    conference: room,
                     id,
                     name: formattedDisplayName
                 }));
@@ -1916,6 +1917,7 @@ export default {
                 switch (name) {
                 case 'raisedHand':
                     APP.store.dispatch(participantUpdated({
+                        conference: room,
                         id: participant.getId(),
                         raisedHand: newValue === 'true'
                     }));
@@ -2015,6 +2017,7 @@ export default {
         APP.UI.addListener(UIEvents.EMAIL_CHANGED, this.changeLocalEmail);
         room.addCommandListener(this.commands.defaults.EMAIL, (data, from) => {
             APP.store.dispatch(participantUpdated({
+                conference: room,
                 id: from,
                 email: data.value
             }));
@@ -2026,6 +2029,7 @@ export default {
             (data, from) => {
                 APP.store.dispatch(
                     participantUpdated({
+                        conference: room,
                         id: from,
                         avatarURL: data.value
                     }));
@@ -2035,6 +2039,7 @@ export default {
             (data, from) => {
                 APP.store.dispatch(
                     participantUpdated({
+                        conference: room,
                         id: from,
                         avatarID: data.value
                     }));
@@ -2579,6 +2584,12 @@ export default {
         const localId = localParticipant.id;
 
         APP.store.dispatch(participantUpdated({
+            // XXX Only the local participant is allowed to update without
+            // stating the JitsiConference instance (i.e. participant property
+            // `conference` for a remote participant) because the local
+            // participant is uniquely identified by the very fact that there is
+            // only one local participant.
+
             id: localId,
             local: true,
             email: formattedEmail
@@ -2606,6 +2617,12 @@ export default {
         }
 
         APP.store.dispatch(participantUpdated({
+            // XXX Only the local participant is allowed to update without
+            // stating the JitsiConference instance (i.e. participant property
+            // `conference` for a remote participant) because the local
+            // participant is uniquely identified by the very fact that there is
+            // only one local participant.
+
             id,
             local: true,
             avatarURL: formattedUrl
@@ -2662,6 +2679,12 @@ export default {
         }
 
         APP.store.dispatch(participantUpdated({
+            // XXX Only the local participant is allowed to update without
+            // stating the JitsiConference instance (i.e. participant property
+            // `conference` for a remote participant) because the local
+            // participant is uniquely identified by the very fact that there is
+            // only one local participant.
+
             id,
             local: true,
             name: formattedNickname
diff --git a/react/features/base/conference/actions.js b/react/features/base/conference/actions.js
index b07714fac..8c18b7f1d 100644
--- a/react/features/base/conference/actions.js
+++ b/react/features/base/conference/actions.js
@@ -125,13 +125,14 @@ function _addConferenceListeners(conference, dispatch) {
     conference.on(
         JitsiConferenceEvents.DISPLAY_NAME_CHANGED,
         (id, displayName) => dispatch(participantUpdated({
+            conference,
             id,
             name: displayName.substr(0, MAX_DISPLAY_NAME_LENGTH)
         })));
 
     conference.on(
         JitsiConferenceEvents.DOMINANT_SPEAKER_CHANGED,
-        (...args) => dispatch(dominantSpeakerChanged(...args)));
+        id => dispatch(dominantSpeakerChanged(id, conference)));
 
     conference.on(
         JitsiConferenceEvents.PARTICIPANT_CONN_STATUS_CHANGED,
@@ -155,18 +156,21 @@ function _addConferenceListeners(conference, dispatch) {
     conference.addCommandListener(
         AVATAR_ID_COMMAND,
         (data, id) => dispatch(participantUpdated({
+            conference,
             id,
             avatarID: data.value
         })));
     conference.addCommandListener(
         AVATAR_URL_COMMAND,
         (data, id) => dispatch(participantUpdated({
+            conference,
             id,
             avatarURL: data.value
         })));
     conference.addCommandListener(
         EMAIL_COMMAND,
         (data, id) => dispatch(participantUpdated({
+            conference,
             id,
             email: data.value
         })));
diff --git a/react/features/base/jwt/middleware.js b/react/features/base/jwt/middleware.js
index 75664a74d..ee1067741 100644
--- a/react/features/base/jwt/middleware.js
+++ b/react/features/base/jwt/middleware.js
@@ -143,7 +143,10 @@ function _overwriteLocalParticipant(
 
     if ((avatarURL || email || name)
             && (localParticipant = getLocalParticipant(getState))) {
-        const newProperties: Object = { id: localParticipant.id };
+        const newProperties: Object = {
+            id: localParticipant.id,
+            local: true
+        };
 
         if (avatarURL) {
             newProperties.avatarURL = avatarURL;
@@ -264,7 +267,10 @@ function _undoOverwriteLocalParticipant(
 
     if ((avatarURL || name || email)
             && (localParticipant = getLocalParticipant(getState))) {
-        const newProperties: Object = { id: localParticipant.id };
+        const newProperties: Object = {
+            id: localParticipant.id,
+            local: true
+        };
 
         if (avatarURL === localParticipant.avatarURL) {
             newProperties.avatarURL = undefined;
diff --git a/react/features/base/participants/actions.js b/react/features/base/participants/actions.js
index b08cafeb9..59575e306 100644
--- a/react/features/base/participants/actions.js
+++ b/react/features/base/participants/actions.js
@@ -22,17 +22,23 @@ import { getLocalParticipant } from './functions';
  * Create an action for when dominant speaker changes.
  *
  * @param {string} id - Participant's ID.
+ * @param {JitsiConference} conference - The {@code JitsiConference} associated
+ * with the participant identified by the specified {@code id}. Only the local
+ * participant is allowed to not specify an associated {@code JitsiConference}
+ * instance.
  * @returns {{
  *     type: DOMINANT_SPEAKER_CHANGED,
  *     participant: {
+ *         conference: JitsiConference,
  *         id: string
  *     }
  * }}
  */
-export function dominantSpeakerChanged(id) {
+export function dominantSpeakerChanged(id, conference) {
     return {
         type: DOMINANT_SPEAKER_CHANGED,
         participant: {
+            conference,
             id
         }
     };
diff --git a/react/features/base/participants/functions.js b/react/features/base/participants/functions.js
index 64957fca3..33fdda0c4 100644
--- a/react/features/base/participants/functions.js
+++ b/react/features/base/participants/functions.js
@@ -127,9 +127,7 @@ export function getLocalParticipant(stateful: Object | Function) {
  * @private
  * @returns {(Participant|undefined)}
  */
-export function getParticipantById(
-        stateful: Object | Function,
-        id: string) {
+export function getParticipantById(stateful: Object | Function, id: string) {
     const participants = _getAllParticipants(stateful);
 
     return participants.find(p => p.id === id);
diff --git a/react/features/base/participants/middleware.js b/react/features/base/participants/middleware.js
index 61735812d..a4c99faf0 100644
--- a/react/features/base/participants/middleware.js
+++ b/react/features/base/participants/middleware.js
@@ -63,20 +63,19 @@ MiddlewareRegistry.register(store => next => action => {
 
     case DOMINANT_SPEAKER_CHANGED: {
         // Ensure the raised hand state is cleared for the dominant speaker.
+
+        const { conference, id } = action.participant;
         const participant = getLocalParticipant(store.getState());
 
-        if (participant) {
-            const { id } = action.participant;
-
-            store.dispatch(participantUpdated({
+        participant
+            && store.dispatch(participantUpdated({
+                conference,
                 id,
                 local: participant.id === id,
                 raisedHand: false
             }));
-        }
 
-        typeof APP === 'object'
-            && APP.UI.markDominantSpeaker(action.participant.id);
+        typeof APP === 'object' && APP.UI.markDominantSpeaker(id);
 
         break;
     }
diff --git a/react/features/base/participants/reducer.js b/react/features/base/participants/reducer.js
index 260432e52..20d86aadf 100644
--- a/react/features/base/participants/reducer.js
+++ b/react/features/base/participants/reducer.js
@@ -32,12 +32,24 @@ import { LOCAL_PARTICIPANT_DEFAULT_ID, PARTICIPANT_ROLE } from './constants';
 declare var APP: Object;
 
 /**
- * These properties should not be bulk assigned when updating a particular
- * @see Participant.
+ * The participant properties which cannot be updated through
+ * {@link PARTICIPANT_UPDATED}. They either identify the participant or can only
+ * be modified through property-dedicated actions.
+ *
  * @type {string[]}
  */
-const PARTICIPANT_PROPS_TO_OMIT_WHEN_UPDATE
-    = [ 'dominantSpeaker', 'id', 'local', 'pinned' ];
+const PARTICIPANT_PROPS_TO_OMIT_WHEN_UPDATE = [
+
+    // The following properties identify the participant:
+    'conference',
+    'id',
+    'local',
+
+    // The following properties can only be modified through property-dedicated
+    // actions:
+    'dominantSpeaker',
+    'pinned'
+];
 
 /**
  * Listen for actions which add, remove, or update the set of participants in
diff --git a/react/features/toolbox/components/web/Toolbox.js b/react/features/toolbox/components/web/Toolbox.js
index d418b3076..d04cbe749 100644
--- a/react/features/toolbox/components/web/Toolbox.js
+++ b/react/features/toolbox/components/web/Toolbox.js
@@ -505,6 +505,12 @@ class Toolbox extends Component<Props> {
         const { _localParticipantID, _raisedHand } = this.props;
 
         this.props.dispatch(participantUpdated({
+            // XXX Only the local participant is allowed to update without
+            // stating the JitsiConference instance (i.e. participant property
+            // `conference` for a remote participant) because the local
+            // participant is uniquely identified by the very fact that there is
+            // only one local participant.
+
             id: _localParticipantID,
             local: true,
             raisedHand: !_raisedHand