diff --git a/libs/cyclone/foreign.sld b/libs/cyclone/foreign.sld
index edc1c669..391f1eea 100644
--- a/libs/cyclone/foreign.sld
+++ b/libs/cyclone/foreign.sld
@@ -14,6 +14,7 @@
   (export
    opaque?
    opaque-null?
+   make-opaque
    
    c-code
    c-value
@@ -31,6 +32,11 @@
       "Cyc_check_opaque(data, p);
        return_closcall1(data, k, make_boolean(opaque_ptr(p) == NULL));")
 
+    (define-c make-opaque
+      "(void *data, int argc, closure _, object k)"
+      "make_c_opaque(opq, NULL);
+       return_closcall1(data, k, &opq);")
+
     ;; (c-define-type name type (pack (unpack)))
     (define-syntax c-define-type
       (er-macro-transformer