diff --git a/test-bn.scm b/test-bn.scm
new file mode 100644
index 00000000..a6f6865a
--- /dev/null
+++ b/test-bn.scm
@@ -0,0 +1,8 @@
+(import (scheme base) (scheme write) (scheme repl))
+
+ (define-c bn-test
+   "(void *data, int argc, closure _, object k, object fx)"
+   " object bn = Cyc_int2bignum2(data, fx);
+     return_closcall1(data, k, bn); ")
+
+ (repl)