diff --git a/lib/onelogin/ruby-saml/utils.rb b/lib/onelogin/ruby-saml/utils.rb
index 40ad313e..b66f6d77 100644
--- a/lib/onelogin/ruby-saml/utils.rb
+++ b/lib/onelogin/ruby-saml/utils.rb
@@ -34,7 +34,7 @@ class Utils
       $)x.freeze
 
       UUID_PREFIX = '_'
-      @@prefix = '_'.freeze
+      @@prefix = '_'
 
       # Checks if the x509 cert provided is expired.
       #