diff --git a/app/models/api_key.rb b/app/models/api_key.rb
index 87b24af11..c4bd06ea4 100644
--- a/app/models/api_key.rb
+++ b/app/models/api_key.rb
@@ -7,10 +7,9 @@ class ApiKey < ApplicationRecord
   belongs_to :user
   has_many :daily_api_usages, dependent: :destroy
 
-  before_create :set_value
+  validates :value, uniqueness: true
 
-  # TODO: Ensure that value is unique
-  # There should be a validation here and a unique index in the schema
+  before_create :set_value
 
   sig { params(value: String).returns(T.nilable(ApiKey)) }
   def self.find_valid(value)
@@ -33,6 +32,7 @@ def self.daily_limit_with_default(value)
 
   private
 
+  # TODO: Retry if api key value is not unique
   sig { void }
   def set_value
     self.value = SecureRandom.base58(20)
diff --git a/db/migrate/20240808005105_add_unique_index_to_api_key_value.rb b/db/migrate/20240808005105_add_unique_index_to_api_key_value.rb
new file mode 100644
index 000000000..b5eaff1a7
--- /dev/null
+++ b/db/migrate/20240808005105_add_unique_index_to_api_key_value.rb
@@ -0,0 +1,7 @@
+class AddUniqueIndexToApiKeyValue < ActiveRecord::Migration[7.1]
+  def change
+    # Recreate the index and make it unique
+    remove_index :api_keys, :value
+    add_index :api_keys, :value, unique: true
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 636083f4e..c2b6d931a 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[7.1].define(version: 2024_07_31_043561) do
+ActiveRecord::Schema[7.1].define(version: 2024_08_08_005105) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
   enable_extension "postgis"
@@ -97,7 +97,7 @@
     t.datetime "created_at", precision: nil, null: false
     t.datetime "updated_at", precision: nil, null: false
     t.index ["user_id"], name: "index_api_keys_on_user_id"
-    t.index ["value"], name: "index_api_keys_on_value"
+    t.index ["value"], name: "index_api_keys_on_value", unique: true
   end
 
   create_table "application_redirects", id: :serial, force: :cascade do |t|