diff --git a/src/db/events-db.cpp b/src/db/events-db.cpp
index ae2f96949..2ade6da98 100644
--- a/src/db/events-db.cpp
+++ b/src/db/events-db.cpp
@@ -267,10 +267,11 @@ EventsDb::EventsDb () : AbstractDb(*new EventsDbPrivate) {}
 				soci::use(static_cast<int>(state)), soci::use(messageEventId), soci::use(sipAddressId)
 		);
 		statement.execute(true);
-		if (statement.get_affected_rows() == 0)
+		if (statement.get_affected_rows() == 0 && state != ChatMessage::State::Displayed) {
 			*session << "INSERT INTO message_participant (message_event_id, sip_address_id, state)"
 				"  VALUES (:messageEventId, :sipAddressId, :state)",
 				soci::use(messageEventId), soci::use(sipAddressId), soci::use(static_cast<int>(state));
+		}
 	}
 
 // -----------------------------------------------------------------------------
@@ -526,6 +527,26 @@ EventsDb::EventsDb () : AbstractDb(*new EventsDbPrivate) {}
 			"    REFERENCES message_event(event_id)"
 			"    ON DELETE CASCADE"
 			")";
+
+		// Trigger to delete participant_message cache entries.
+		string displayedId = Utils::toString(static_cast<int>(ChatMessage::State::Displayed));
+		string participantMessageDeleter =
+		  "CREATE TRIGGER IF NOT EXISTS message_participant_deleter"
+			"  AFTER UPDATE OF state ON message_participant FOR EACH ROW"
+			"  WHEN NEW.state = ";
+		participantMessageDeleter += displayedId;
+		participantMessageDeleter += "  AND (SELECT COUNT(*) FROM ("
+			"    SELECT state FROM message_participant WHERE"
+			"    NEW.message_event_id = message_participant.message_event_id"
+			"    AND state <> ";
+		participantMessageDeleter += displayedId;
+		participantMessageDeleter += "    LIMIT 1"
+			"  )) = 0"
+			"  BEGIN"
+			"  DELETE FROM message_participant WHERE NEW.message_event_id = message_participant.message_event_id;"
+			"  END";
+
+		*session << participantMessageDeleter;
 	}
 
 	bool EventsDb::addEvent (const EventLog &eventLog) {