diff --git a/application/src/main/data/upgrade/3.5.1/schema_update.sql b/application/src/main/data/upgrade/3.5.1/schema_update.sql
index c8efd4390e..5aab5d740b 100644
--- a/application/src/main/data/upgrade/3.5.1/schema_update.sql
+++ b/application/src/main/data/upgrade/3.5.1/schema_update.sql
@@ -127,6 +127,8 @@ UPDATE resource
 
 ALTER TABLE notification_request ALTER COLUMN info SET DATA TYPE varchar(1000000);
 
+DELETE FROM alarm WHERE tenant_id NOT IN (SELECT id FROM tenant);
+
 CREATE TABLE IF NOT EXISTS alarm_types (
     tenant_id uuid NOT NULL,
     type varchar(255) NOT NULL,
diff --git a/application/src/main/java/org/thingsboard/server/service/install/SqlDatabaseUpgradeService.java b/application/src/main/java/org/thingsboard/server/service/install/SqlDatabaseUpgradeService.java
index 2e2b3e96be..4bb29426c9 100644
--- a/application/src/main/java/org/thingsboard/server/service/install/SqlDatabaseUpgradeService.java
+++ b/application/src/main/java/org/thingsboard/server/service/install/SqlDatabaseUpgradeService.java
@@ -731,8 +731,8 @@ public class SqlDatabaseUpgradeService implements DatabaseEntitiesUpgradeService
                 break;
             case "3.5.1":
                 try (Connection conn = DriverManager.getConnection(dbUrl, dbUserName, dbPassword)) {
-                    log.info("Updating schema ...");
                     if (isOldSchema(conn, 3005001)) {
+                        log.info("Updating schema ...");
                         schemaUpdateFile = Paths.get(installScripts.getDataDir(), "upgrade", "3.5.1", SCHEMA_UPDATE_SQL);
                         loadSql(schemaUpdateFile, conn);
 
@@ -762,8 +762,10 @@ public class SqlDatabaseUpgradeService implements DatabaseEntitiesUpgradeService
                         }
 
                         conn.createStatement().execute("UPDATE tb_schema_settings SET schema_version = 3005002;");
+                        log.info("Schema updated to version 3.5.2.");
+                    } else {
+                        log.info("Skip schema re-update to version 3.5.2. Use env flag 'SKIP_SCHEMA_VERSION_CHECK' to force the re-update.");
                     }
-                    log.info("Schema updated.");
                 } catch (Exception e) {
                     log.error("Failed updating schema!!!", e);
                 }