diff --git a/test-fixnum-packing.c b/test-fixnum-packing.c
new file mode 100644
index 00000000..af7aabb5
--- /dev/null
+++ b/test-fixnum-packing.c
@@ -0,0 +1,27 @@
+#include "include/cyclone/types.h"
+
+#define my_obj_is_int(x)  ((unsigned long)(x) & (unsigned long)1)
+//
+///**
+// * Convert from an object to an integer.
+// */
+#define my_obj_obj2int(x) ((long)(x)>>1)
+//
+//+#define sexp_make_fixnum(n)    ((sexp) ((((sexp_sint_t)(n))*(sexp_sint_t)(1uL<<SEXP_FIXNUM_BITS)) | SEXP_FIXNUM_TAG))
+//+#define sexp_unbox_fixnum(n)   (((sexp_sint_t)((sexp_uint_t)(n) & ~SEXP_FIXNUM_TAG))/(sexp_sint_t)(1uL<<SEXP_FIXNUM_BITS))
+//
+///**
+// * Convert from an integer to an object.
+// */
+#define my_obj_int2obj(c) ((void *)((((long)c)<<1) | 1))
+
+void main()
+{
+  object tmp;
+  int n = -1;
+
+  tmp = my_obj_int2obj(-1);
+  printf("%p\n", my_obj_int2obj(-1));
+  printf("%d\n", my_obj_obj2int(tmp));
+  printf("%d\n", my_obj_is_int(tmp));
+}