diff --git a/app/models/site/repository.rb b/app/models/site/repository.rb
index d969522..43dae27 100644
--- a/app/models/site/repository.rb
+++ b/app/models/site/repository.rb
@@ -44,8 +44,8 @@ class Site
     #
     # @return [Integer]
     def fetch
-      if origin.check_connection :fetch
-        rugged.fetch(origin)[:received_objects]
+      if origin.check_connection(:fetch, credentials: credentials)
+        rugged.fetch(origin, credentials: credentials)[:received_objects]
       else
         0
       end
@@ -149,6 +149,26 @@ class Site
 
     private
 
+    # Si Sutty tiene una llave privada de tipo ED25519, devuelve las
+    # credenciales necesarias para trabajar con repositorios remotos.
+    #
+    # @return [Nil, Rugged::Credentials::SshKey]
+    def credentials
+      return unless File.exist? private_key
+
+      @credentials ||= Rugged::Credentials::SshKey.new username: 'git', publickey: public_key, privatekey: private_key
+    end
+
+    # @return [String]
+    def public_key
+      @public_key ||= Rails.root.join('.ssh', 'id_ed25519.pub')
+    end
+
+    # @return [String]
+    def private_key
+      @private_key ||= Rails.root.join('.ssh', 'id_ed25519')
+    end
+
     def relativize(file)
       Pathname.new(file).relative_path_from(Pathname.new(path)).to_s
     end