diff --git a/ffi-tools/ffi-tools-rts.scm b/ffi-tools/ffi-tools-rts.scm
index bdd07ff..aa08ec2 100644
--- a/ffi-tools/ffi-tools-rts.scm
+++ b/ffi-tools/ffi-tools-rts.scm
@@ -7,6 +7,10 @@
   (open scheme srfi-23 external-calls)
   (begin
     
+    (define-exported-binding "length" length)
+    (define-exported-binding "boolean?" boolean?)
+    (define-exported-binding "integer?" integer?)
+
     (define-syntax lookup-shared-value
       (syntax-rules ()
 	((lookup-shared-value %s)