diff --git a/coreapi/carddav.c b/coreapi/carddav.c
index 13554178a..9ad732b87 100644
--- a/coreapi/carddav.c
+++ b/coreapi/carddav.c
@@ -75,7 +75,12 @@ static void linphone_carddav_sync_done(LinphoneCardDavContext *cdc, bool_t succe
 static int find_matching_friend(LinphoneFriend *lf1, LinphoneFriend *lf2) {
 	LinphoneVCard *lvc1 = linphone_friend_get_vcard(lf1);
 	LinphoneVCard *lvc2 = linphone_friend_get_vcard(lf2);
-	return strcmp(linphone_vcard_get_uid(lvc1), linphone_vcard_get_uid(lvc2));
+	const char *uid1 = linphone_vcard_get_uid(lvc1);
+	const char *uid2 = linphone_vcard_get_uid(lvc2);
+	if (!uid1 || !uid2) {
+		return 1;
+	}
+	return strcmp(uid1, uid2);
 }
 
 static void linphone_carddav_vcards_pulled(LinphoneCardDavContext *cdc, MSList *vCards) {
@@ -150,7 +155,12 @@ end:
 static int find_matching_vcard(LinphoneCardDavResponse *response, LinphoneFriend *lf) {
 	LinphoneVCard *lvc1 = linphone_vcard_new_from_vcard4_buffer(response->vcard);
 	LinphoneVCard *lvc2 = linphone_friend_get_vcard(lf);
-	return strcmp(linphone_vcard_get_uid(lvc1), linphone_vcard_get_uid(lvc2));
+	const char *uid1 = linphone_vcard_get_uid(lvc1);
+	const char *uid2 = linphone_vcard_get_uid(lvc2);
+	if (!uid1 || !uid2) {
+		return 1;
+	}
+	return strcmp(uid1, uid2);
 }
 
 static void linphone_carddav_vcards_fetched(LinphoneCardDavContext *cdc, MSList *vCards) {
diff --git a/coreapi/vcard.cc b/coreapi/vcard.cc
index 039ec200f..c8d94c5b2 100644
--- a/coreapi/vcard.cc
+++ b/coreapi/vcard.cc
@@ -82,6 +82,8 @@ extern "C" LinphoneVCard* linphone_vcard_new_from_vcard4_buffer(const char *buff
 		if (belCard) {
 			vCard = linphone_vcard_new();
 			vCard->belCard = belCard;
+		} else {
+			ms_error("Couldn't parse buffer %s", buffer);
 		}
 	}
 	return vCard;
@@ -155,7 +157,7 @@ extern "C" MSList* linphone_vcard_get_sip_addresses(const LinphoneVCard *vCard)
 }
 
 extern "C" const char* linphone_vcard_get_uid(const LinphoneVCard *vCard) {
-	if (vCard->belCard->getUniqueId()) {
+	if (vCard && vCard->belCard->getUniqueId()) {
 		return vCard->belCard->getUniqueId()->getValue().c_str();
 	}
 	return NULL;
@@ -166,6 +168,7 @@ extern "C" void linphone_vcard_set_etag(LinphoneVCard *vCard, const char * etag)
 }
 
 extern "C" const char* linphone_vcard_get_etag(const LinphoneVCard *vCard) {
+	if (!vCard) return NULL;
 	return vCard->etag;
 }
 
@@ -174,5 +177,6 @@ extern "C" void linphone_vcard_set_url(LinphoneVCard *vCard, const char * url) {
 }
 
 extern "C" const char* linphone_vcard_get_url(const LinphoneVCard *vCard) {
+	if (!vCard) return NULL;
 	return vCard->url;
 }
\ No newline at end of file
diff --git a/tester/vcard_tester.c b/tester/vcard_tester.c
index f6531eb40..896a4c24d 100644
--- a/tester/vcard_tester.c
+++ b/tester/vcard_tester.c
@@ -239,9 +239,79 @@ static void carddav_sync(void) {
 	linphone_carddav_synchronize(c);
 	
 	wait_for_until(manager->lc, NULL, &stats->new_contact_count, 1, 2000);
+	BC_ASSERT_EQUAL(stats->new_contact_count, 1, int, "%i");
 	wait_for_until(manager->lc, NULL, &stats->sync_done_count, 1, 2000);
+	BC_ASSERT_EQUAL(stats->sync_done_count, 1, int, "%i");
 	linphone_core_manager_destroy(manager);
 }
+
+static void carddav_sync_2(void) {
+	LinphoneCoreManager *manager = linphone_core_manager_new2("carddav_rc", FALSE);
+	LinphoneCardDavContext *c = linphone_core_create_carddav_context(manager->lc);
+	LinphoneCardDAVStats *stats = (LinphoneCardDAVStats *)ms_new0(LinphoneCardDAVStats, 1);
+	LinphoneFriend *lf = linphone_friend_new_with_address("\"Sylvain\" <sip:sylvain@sip.linphone.org>");
+	char *friends_db = create_filepath(bc_tester_get_writable_dir_prefix(), "friends", "db");
+	
+	unlink(friends_db);
+	linphone_core_set_friends_database_path(manager->lc, friends_db);
+	linphone_core_add_friend(manager->lc, lf);
+	linphone_friend_unref(lf);
+	
+	BC_ASSERT_PTR_NOT_NULL_FATAL(c);
+	BC_ASSERT_PTR_NOT_NULL(c->server_url);
+	BC_ASSERT_PTR_NOT_NULL(c->username);
+	BC_ASSERT_PTR_NOT_NULL(c->ha1);
+	
+	linphone_carddav_set_user_data(c, stats);
+	linphone_carddav_set_synchronization_done_callback(c, carddav_sync_done);
+	linphone_carddav_set_new_contact_callback(c, carddav_new_contact);
+	linphone_carddav_set_removed_contact_callback(c, carddav_removed_contact);
+	linphone_carddav_set_updated_contact_callback(c, carddav_updated_contact);
+	
+	linphone_carddav_synchronize(c);
+	
+	wait_for_until(manager->lc, NULL, &stats->new_contact_count, 1, 2000);
+	BC_ASSERT_EQUAL(stats->new_contact_count, 1, int, "%i");
+	wait_for_until(manager->lc, NULL, &stats->removed_contact_count, 1, 2000);
+	BC_ASSERT_EQUAL(stats->removed_contact_count, 1, int, "%i");
+	wait_for_until(manager->lc, NULL, &stats->sync_done_count, 1, 2000);
+	BC_ASSERT_EQUAL(stats->sync_done_count, 1, int, "%i");
+	linphone_core_manager_destroy(manager);
+}
+
+static void carddav_sync_3(void) {
+	LinphoneCoreManager *manager = linphone_core_manager_new2("carddav_rc", FALSE);
+	LinphoneCardDavContext *c = linphone_core_create_carddav_context(manager->lc);
+	LinphoneCardDAVStats *stats = (LinphoneCardDAVStats *)ms_new0(LinphoneCardDAVStats, 1);
+	LinphoneVCard *lvc = linphone_vcard_new_from_vcard4_buffer("BEGIN:VCARD\r\nVERSION:4.0\r\nUID:79100a4d-2806-482f-bf27-0e09dc47149b\r\nFN:Sylvain Berfini\r\nIMPP;TYPE=work:sip:sylvain@sip.linphone.org\r\nEND:VCARD\r\n");
+	LinphoneFriend *lf = linphone_friend_new_from_vcard(lvc);
+	char *friends_db = create_filepath(bc_tester_get_writable_dir_prefix(), "friends", "db");
+	
+	unlink(friends_db);
+	linphone_core_set_friends_database_path(manager->lc, friends_db);
+	linphone_core_add_friend(manager->lc, lf);
+	linphone_friend_unref(lf);
+	
+	BC_ASSERT_PTR_NOT_NULL_FATAL(c);
+	BC_ASSERT_PTR_NOT_NULL(c->server_url);
+	BC_ASSERT_PTR_NOT_NULL(c->username);
+	BC_ASSERT_PTR_NOT_NULL(c->ha1);
+	
+	linphone_carddav_set_user_data(c, stats);
+	linphone_carddav_set_synchronization_done_callback(c, carddav_sync_done);
+	linphone_carddav_set_new_contact_callback(c, carddav_new_contact);
+	linphone_carddav_set_removed_contact_callback(c, carddav_removed_contact);
+	linphone_carddav_set_updated_contact_callback(c, carddav_updated_contact);
+	
+	linphone_carddav_synchronize(c);
+	
+	wait_for_until(manager->lc, NULL, &stats->updated_contact_count, 1, 2000);
+	BC_ASSERT_EQUAL(stats->updated_contact_count, 1, int, "%i");
+	wait_for_until(manager->lc, NULL, &stats->sync_done_count, 1, 2000);
+	BC_ASSERT_EQUAL(stats->sync_done_count, 1, int, "%i");
+	linphone_core_manager_destroy(manager);
+}
+
 #else
 static void dummy_test(void) {
 	
@@ -258,6 +328,8 @@ test_t vcard_tests[] = {
 	{ "Friends storage in sqlite database", friends_sqlite_storage },
 #endif
 	{ "CardDAV synchronization", carddav_sync },
+	{ "CardDAV synchronization 2", carddav_sync_2 },
+	{ "CardDAV synchronization 3", carddav_sync_3 },
 #else
 	{ "Dummy test", dummy_test }
 #endif