diff --git a/db/migrate/20260218120000_restore_unique_index_on_board_publication_key.rb b/db/migrate/20260218120000_restore_unique_index_on_board_publication_key.rb
new file mode 100644
index 000000000..dfcd5edaf
--- /dev/null
+++ b/db/migrate/20260218120000_restore_unique_index_on_board_publication_key.rb
@@ -0,0 +1,7 @@
+class RestoreUniqueIndexOnBoardPublicationKey < ActiveRecord::Migration[8.2]
+  def change
+    add_index :board_publications, :key, unique: true
+    add_index :board_publications, :account_id
+    remove_index :board_publications, [:account_id, :key]
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index e74a97212..20cb0d161 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.2].define(version: 2026_02_13_170100) do
+ActiveRecord::Schema[8.2].define(version: 2026_02_18_120000) do
   create_table "accesses", id: :uuid, charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.datetime "accessed_at"
     t.uuid "account_id", null: false
@@ -147,8 +147,9 @@ ActiveRecord::Schema[8.2].define(version: 2026_02_13_170100) do
     t.datetime "created_at", null: false
     t.string "key"
     t.datetime "updated_at", null: false
-    t.index ["account_id", "key"], name: "index_board_publications_on_account_id_and_key"
+    t.index ["account_id"], name: "index_board_publications_on_account_id"
     t.index ["board_id"], name: "index_board_publications_on_board_id"
+    t.index ["key"], name: "index_board_publications_on_key", unique: true
   end
 
   create_table "boards", id: :uuid, charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
diff --git a/db/schema_sqlite.rb b/db/schema_sqlite.rb
index e06492288..c8ce19e07 100644
--- a/db/schema_sqlite.rb
+++ b/db/schema_sqlite.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.2].define(version: 2026_02_13_170100) do
+ActiveRecord::Schema[8.2].define(version: 2026_02_18_120000) do
   create_table "accesses", id: :uuid, force: :cascade do |t|
     t.datetime "accessed_at"
     t.uuid "account_id", null: false
@@ -147,8 +147,9 @@ ActiveRecord::Schema[8.2].define(version: 2026_02_13_170100) do
     t.datetime "created_at", null: false
     t.string "key", limit: 255
     t.datetime "updated_at", null: false
-    t.index ["account_id", "key"], name: "index_board_publications_on_account_id_and_key"
+    t.index ["account_id"], name: "index_board_publications_on_account_id"
     t.index ["board_id"], name: "index_board_publications_on_board_id"
+    t.index ["key"], name: "index_board_publications_on_key", unique: true
   end
 
   create_table "boards", id: :uuid, force: :cascade do |t|