diff --git a/app/models/label.rb b/app/models/label.rb
index e2379bb6d77e709ebf4ea3d91cfe12d65b872772..941520b4c748418347a06cf240717f7bd8153d20 100644
--- a/app/models/label.rb
+++ b/app/models/label.rb
@@ -9,7 +9,10 @@ class Label < ActiveRecord::Base
   validates :project, presence: true
 
   # Don't allow '?', '&', and ',' for label titles
-  validates :title, presence: true, format: { with: /\A[^&\?,&]*\z/ }
+  validates :title,
+            presence: true,
+            format: { with: /\A[^&\?,&]*\z/ },
+            uniqueness: true
 
   scope :order_by_name, -> { reorder("labels.title ASC") }