diff --git a/src/ikarus.boot b/src/ikarus.boot
index b1f3b8f..3cfeee3 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.guardians.ss b/src/ikarus.guardians.ss
index c0981d1..bf76026 100644
--- a/src/ikarus.guardians.ss
+++ b/src/ikarus.guardians.ss
@@ -20,5 +20,5 @@
                     (set-cdr! x #f)
                     y)))]
           [(obj) 
-           (foreign-call "ikrt_register_guardian" tc obj)
+           (foreign-call "ikrt_register_guardian_pair" (cons tc obj))
            (void)])))))