diff --git a/scheme/interfaces.scm b/scheme/interfaces.scm
index fcda49d..e81e800 100644
--- a/scheme/interfaces.scm
+++ b/scheme/interfaces.scm
@@ -489,6 +489,11 @@
 	  make-output-port make-unbuffered-output-port
 	  make-port-handler
 	  port-handler-buffer-proc     ; extended-ports
+	  port-handler-discloser
+	  port-handler-close
+	  port-handler-ready?
+	  port-handler-steal
+	  
 	  default-buffer-size
 
 	  open-input-port?