diff --git a/app/controllers/api/v1/auth_controller.rb b/app/controllers/api/v1/auth_controller.rb
index 9e5e2768..4f20b934 100644
--- a/app/controllers/api/v1/auth_controller.rb
+++ b/app/controllers/api/v1/auth_controller.rb
@@ -175,7 +175,7 @@ module Api
         def create_or_update_device(user)
           # Handle both string and symbol keys
           device_data = params[:device].permit(:device_id, :device_name, :device_type, :os_version, :app_version)
-          
+
           device = user.mobile_devices.find_or_initialize_by(device_id: device_data[:device_id])
           device.update!(device_data.merge(last_seen_at: Time.current))
           device
diff --git a/app/models/mobile_device.rb b/app/models/mobile_device.rb
index 106b2928..e334e3a8 100644
--- a/app/models/mobile_device.rb
+++ b/app/models/mobile_device.rb
@@ -27,7 +27,7 @@ class MobileDevice < ApplicationRecord
       scopes: "read_write", # Use the configured scope
       confidential: false # Public client for mobile
     )
-    
+
     # Store the association
     update!(oauth_application: app)
     app
@@ -35,7 +35,7 @@ class MobileDevice < ApplicationRecord
 
   def active_tokens
     return Doorkeeper::AccessToken.none unless oauth_application
-    
+
     Doorkeeper::AccessToken
       .where(application: oauth_application)
       .where(resource_owner_id: user_id)
diff --git a/db/schema.rb b/db/schema.rb
index e817a168..b73e3a8d 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[7.2].define(version: 2025_06_18_110736) do
+ActiveRecord::Schema[7.2].define(version: 2025_06_18_120703) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pgcrypto"
   enable_extension "plpgsql"
@@ -441,7 +441,9 @@ ActiveRecord::Schema[7.2].define(version: 2025_06_18_110736) do
     t.datetime "last_seen_at"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.integer "oauth_application_id"
     t.index ["device_id"], name: "index_mobile_devices_on_device_id", unique: true
+    t.index ["oauth_application_id"], name: "index_mobile_devices_on_oauth_application_id"
     t.index ["user_id", "device_id"], name: "index_mobile_devices_on_user_id_and_device_id", unique: true
     t.index ["user_id"], name: "index_mobile_devices_on_user_id"
   end
diff --git a/test/models/api_key_test.rb b/test/models/api_key_test.rb
index d42c2955..d437e2c8 100644
--- a/test/models/api_key_test.rb
+++ b/test/models/api_key_test.rb
@@ -146,7 +146,7 @@ class ApiKeyTest < ActiveSupport::TestCase
     )
 
     assert_not second_key.valid?
-    assert_includes second_key.errors[:user], "can only have one active API key"
+    assert_includes second_key.errors[:user], "can only have one active API key per source (web)"
   end
 
   test "should allow user to have new active key after revoking old one" do