diff --git a/announcement.gemspec b/announcement.gemspec
index 9b173fe..a4e651e 100644
--- a/announcement.gemspec
+++ b/announcement.gemspec
@@ -179,4 +179,5 @@ Gem::Specification.new do |s|
   s.test_files = Dir["test/**/*"]
 
   s.add_dependency "rufus-scheduler", "~> 3.6.0"
+  s.add_dependency "mimemagic" , "0.3.9"
 end