diff --git a/a.out b/a.out
new file mode 100755
index 00000000..1e1fd59f
Binary files /dev/null and b/a.out differ
diff --git a/test/signatures.c b/test/signatures.c
new file mode 100644
index 00000000..bcebe993
--- /dev/null
+++ b/test/signatures.c
@@ -0,0 +1,55 @@
+#include <stdio.h>
+#include <stdint.h>
+
+struct H64 {
+  uint8_t hash[64];
+};
+struct Hhh {
+  struct H64 hash;
+};
+struct Purpose {
+  uint32_t size;
+  uint32_t purpose;
+};
+
+struct PS {
+  struct Purpose purpose;
+  struct Hhh h;
+  uint32_t noreveal_index;
+};
+
+int main(void) {
+    struct Purpose purpose;
+    struct PS ps;
+
+    purpose.size = 3 * 4 + 64;
+    purpose.purpose = 1050;
+
+    struct Hhh h = {
+        .hash = {
+            .hash = {
+                1 , 2 , 3 , 4 , 5, 6, 7, 8,
+                9 , 10, 11, 12, 13, 14, 15, 16,
+                17, 18, 19, 20, 21, 22, 23, 24,
+                25, 26, 27, 28, 29, 30, 31, 32,
+                33, 34, 35, 36, 37, 38, 39, 40,
+                41, 42, 43, 44, 45, 46, 47, 48,
+                49, 50, 51, 52, 53, 54, 55, 56,
+                57, 58, 59, 60, 61, 62, 63, 64
+            }
+        }
+    };
+
+    uint32_t noreveal_index = 0;
+
+    ps.purpose = purpose;
+    ps.h = h;
+    ps.noreveal_index = noreveal_index;
+
+
+    fwrite(&ps, sizeof(ps), 1, stdout);
+
+    // printf("\n");
+
+    return 0;
+}
diff --git a/test/signatures.output b/test/signatures.output
new file mode 100644
index 00000000..53eb1eba
Binary files /dev/null and b/test/signatures.output differ
diff --git a/test/test.ml b/test/test.ml
index d84a6004..3b0966e5 100644
--- a/test/test.ml
+++ b/test/test.ml
@@ -74,9 +74,10 @@ let () =
 
 let () =
   let open Binary_formats.WithdrawConfirmationPS in
-  let str64 = String.make 64 '0' in
+  let str64 = String.init 64 (fun i -> Char.unsafe_chr (i + 1)) in
   let dummy_t = { h_planchets= { v= { v= str64 } }; noreveal_index= 0_l } in
   let size' = Bin.size_of_value bin dummy_t |> Option.get in
   assert (size = size');
   assert (size = 76);
-  ()
+  let raw_str = Bin.to_string bin dummy_t in
+  Printf.printf "%s" raw_str; ()
diff --git a/test/test.output b/test/test.output
new file mode 100644
index 00000000..53eb1eba
Binary files /dev/null and b/test/test.output differ