diff --git a/src/main/resources/db/migration/V3__add_router_unique_constraints.sql b/src/main/resources/db/migration/V3__add_router_unique_constraints.sql
new file mode 100644
index 0000000..e836f0b
--- /dev/null
+++ b/src/main/resources/db/migration/V3__add_router_unique_constraints.sql
@@ -0,0 +1,2 @@
+ALTER TABLE routers
+ADD CONSTRAINT uk_routers_lan_subnet UNIQUE (lan_subnet);
\ No newline at end of file