diff --git a/app/libs/educoder_oauth/service.rb b/app/libs/educoder_oauth/service.rb
index dfa7adf23..c53ca34ce 100644
--- a/app/libs/educoder_oauth/service.rb
+++ b/app/libs/educoder_oauth/service.rb
@@ -7,7 +7,7 @@ module EducoderOauth::Service
     begin 
       Rails.logger.info("[EducoderOauth] [#{method.to_s.upcase}] #{url} || #{params}")
 
-      client = Faraday.new(url: EducoderOauth.base_url, headers: {'X-EDU-Timestamp' => Time.now.to_i})
+      client = Faraday.new(url: EducoderOauth.base_url, headers: {'X-EDU-Timestamp' => "#{Time.now.to_i}"})
       response = client.public_send(method, url, params)
       result = JSON.parse(response.body)