diff --git a/app/models/oic_session.rb b/app/models/oic_session.rb
index 045a123..27e0dcd 100644
--- a/app/models/oic_session.rb
+++ b/app/models/oic_session.rb
@@ -86,7 +86,7 @@ def refresh_access_token!
 
   def self.parse_token(token)
     jwt = token.split('.')
-    return JSON::parse(Base64::decode64(jwt[1]))
+    return JSON::parse(Base64::urlsafe_decode64(jwt[1]))
   end
 
   def claims
@@ -143,7 +143,7 @@ def admin?
 
   def user
     if @user.blank? || id_token_changed?
-      @user = JSON::parse(Base64::decode64(id_token.split('.')[1]))
+      @user = JSON::parse(Base64::urlsafe_decode64(id_token.split('.')[1]))
     end
     return @user
   end
diff --git a/overlays b/overlays
new file mode 120000
index 0000000..d0bfb1b
--- /dev/null
+++ b/overlays
@@ -0,0 +1 @@
+/overlays/redmine_openid_connect_github
\ No newline at end of file