diff --git a/plugins/ldap/README.md b/plugins/ldap/README.md
index b14ca97..706a440 100644
--- a/plugins/ldap/README.md
+++ b/plugins/ldap/README.md
@@ -13,6 +13,7 @@ Dependences
 See the Noosfero install file. After install Noosfero, install LDAP dependences:
 
 $ gem install net-ldap -v 0.3.1
+$ sudo apt-get install ruby-magic
 
 Enable Plugin
 -------------
diff --git a/plugins/ldap/lib/ldap_authentication.rb b/plugins/ldap/lib/ldap_authentication.rb
index eaa7a18..7171858 100644
--- a/plugins/ldap/lib/ldap_authentication.rb
+++ b/plugins/ldap/lib/ldap_authentication.rb
@@ -136,7 +136,7 @@ class LdapAuthentication
   def self.get_attr(entry, attr_name)
     if !attr_name.blank?
       val = entry[attr_name].is_a?(Array) ? entry[attr_name].first : entry[attr_name]
-      charset = Magic.guess_string_mime(val).match(/charset=([^\s]+)/)[1]
+      charset = Magic.guess_string_mime_encoding(val)
       val.encode 'utf-8', charset, invalid: :replace, undef: :replace
     end
   end
--
libgit2 0.21.2