diff --git a/lib/fog/aws/models/compute/server.rb b/lib/fog/aws/models/compute/server.rb
index 9b8e7ac21..8e2b63e55 100644
--- a/lib/fog/aws/models/compute/server.rb
+++ b/lib/fog/aws/models/compute/server.rb
@@ -84,7 +84,7 @@ module Fog
         end
 
         def key_pair=(new_keypair)
-          key_name = new_keypair && new_keypair.name
+          self.key_name = new_keypair && new_keypair.name
         end
 
         def private_key_path