diff --git a/exercises/practice/rotational-cipher/.docs/instructions.append.md b/exercises/practice/rotational-cipher/.docs/instructions.append.md
new file mode 100644
index 0000000..a62a79d
--- /dev/null
+++ b/exercises/practice/rotational-cipher/.docs/instructions.append.md
@@ -0,0 +1,5 @@
+## Reserved Memory
+
+Bytes 64-319 of the linear memory are reserved for the input string.
+
+The input string can be modified in place if desired.
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diff --git a/exercises/practice/rotational-cipher/.meta/proof.ci.wat b/exercises/practice/rotational-cipher/.meta/proof.ci.wat
index 0817d2a..df44c0e 100644
--- a/exercises/practice/rotational-cipher/.meta/proof.ci.wat
+++ b/exercises/practice/rotational-cipher/.meta/proof.ci.wat
@@ -1,6 +1,11 @@
 (module
   (memory (export "mem") 1)
 
+  (global $A i32 (i32.const 65))
+  (global $Z i32 (i32.const 90))
+  (global $a i32 (i32.const 97))
+  (global $z i32 (i32.const 122))
+
   (func $wrap (param $low i32) (param $high i32) (param $value i32) (param $shiftKey i32) (result i32)
       (local $newValue i32)
       (local.set $newValue (local.get $value))
@@ -63,8 +68,8 @@
       ;; shift upper case
       (local.set $value
         (call $wrap 
-          (i32.const 65) 
-          (i32.const 90) 
+          (global.get $A)
+          (global.get $Z)
           (i32.load8_u (local.get $index))
           (local.get $shiftKey)
         )
@@ -73,8 +78,8 @@
       ;; shift lower case
       (local.set $value
         (call $wrap 
-          (i32.const 97) 
-          (i32.const 122) 
+          (global.get $a)
+          (global.get $z)
           (local.get $value)
           (local.get $shiftKey)
         )
diff --git a/exercises/practice/rotational-cipher/rotational-cipher.spec.js b/exercises/practice/rotational-cipher/rotational-cipher.spec.js
index 2577326..4b0d7eb 100644
--- a/exercises/practice/rotational-cipher/rotational-cipher.spec.js
+++ b/exercises/practice/rotational-cipher/rotational-cipher.spec.js
@@ -1,5 +1,4 @@
 import { compileWat, WasmRunner } from "@exercism/wasm-lib";
-import exp from "constants";
 
 let wasmModule;
 let currentInstance;
@@ -58,39 +57,39 @@ describe("Rotational Cipher", () => {
     expect(rotate("a", 0)).toEqual("a");
   });
 
-  test("rotate a by 1", () => {
+  xtest("rotate a by 1", () => {
     expect(rotate("a", 1)).toEqual("b");
   });
 
-  test("rotate a by 26, same output as input", () => {
+  xtest("rotate a by 26, same output as input", () => {
     expect(rotate("a", 26)).toEqual("a");
   });
 
-  test("rotate m by 13", () => {
+  xtest("rotate m by 13", () => {
     expect(rotate("m", 13)).toEqual("z");
   });
 
-  test("rotate n by 13 with wrap around alphabet", () => {
+  xtest("rotate n by 13 with wrap around alphabet", () => {
     expect(rotate("n", 13)).toEqual("a");
   });
 
-  test("rotate capital letters", () => {
+  xtest("rotate capital letters", () => {
     expect(rotate("OMG", 5)).toEqual("TRL");
   });
 
-  test("rotate spaces", () => {
+  xtest("rotate spaces", () => {
     expect(rotate("O M G", 5)).toEqual("T R L");
   });
 
-  test("rotate numbers", () => {
+  xtest("rotate numbers", () => {
     expect(rotate("Testing 1 2 3 testing", 4)).toEqual("Xiwxmrk 1 2 3 xiwxmrk");
   });
 
-  test("rotate punctuation", () => {
+  xtest("rotate punctuation", () => {
     expect(rotate("Let's eat, Grandma!", 21)).toEqual("Gzo'n zvo, Bmviyhv!");
   });
 
-  test("rotate all letters", () => {
+  xtest("rotate all letters", () => {
     expect(rotate("The quick brown fox jumps over the lazy dog.", 13)).toEqual("Gur dhvpx oebja sbk whzcf bire gur ynml qbt.");
   });
 });
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