diff --git a/src/db/events-db.cpp b/src/db/events-db.cpp
index 044561015..6787a060e 100644
--- a/src/db/events-db.cpp
+++ b/src/db/events-db.cpp
@@ -135,13 +135,13 @@ EventsDb::EventsDb () : AbstractDb(*new EventsDbPrivate) {}
 		*session <<
 			"CREATE TABLE IF NOT EXISTS sip_address ("
 			"  id" + primaryKeyAutoIncrementStr() + ","
-			"  value VARCHAR(255) NOT NULL"
+			"  value VARCHAR(255) UNIQUE NOT NULL"
 			")";
 
 		*session <<
 			"CREATE TABLE IF NOT EXISTS event_type ("
 			"  id TINYINT UNSIGNED,"
-			"  value VARCHAR(255) NOT NULL"
+			"  value VARCHAR(255) UNIQUE NOT NULL"
 			")";
 
 		*session <<
@@ -157,13 +157,13 @@ EventsDb::EventsDb () : AbstractDb(*new EventsDbPrivate) {}
 		*session <<
 			"CREATE TABLE IF NOT EXISTS message_state ("
 			"  id TINYINT UNSIGNED,"
-			"  value VARCHAR(255) NOT NULL"
+			"  value VARCHAR(255) UNIQUE NOT NULL"
 			")";
 
 		*session <<
 			"CREATE TABLE IF NOT EXISTS message_direction ("
 			"  id TINYINT UNSIGNED,"
-			"  value VARCHAR(255) NOT NULL"
+			"  value VARCHAR(255) UNIQUE NOT NULL"
 			")";
 
 		*session <<
diff --git a/tester/db/linphone.db b/tester/db/linphone.db
index 607cb323e..8d5c4e69e 100644
Binary files a/tester/db/linphone.db and b/tester/db/linphone.db differ
diff --git a/tester/events-db-tester.cpp b/tester/events-db-tester.cpp
index 9f38bb738..bf110400f 100644
--- a/tester/events-db-tester.cpp
+++ b/tester/events-db-tester.cpp
@@ -37,7 +37,7 @@ static const string getDatabasePath () {
 
 static void open_database () {
 	EventsDb eventsDb;
-	eventsDb.connect(EventsDb::Sqlite3, getDatabasePath());
+	BC_ASSERT_TRUE(eventsDb.connect(EventsDb::Sqlite3, getDatabasePath()));
 }
 
 test_t events_db_tests[] = {