diff --git a/src/core/operations/ConvertLeetSpeak.mjs b/src/core/operations/ConvertLeetSpeak.mjs
index 54fa62f6e7..1a7cb2fcd1 100644
--- a/src/core/operations/ConvertLeetSpeak.mjs
+++ b/src/core/operations/ConvertLeetSpeak.mjs
@@ -18,7 +18,7 @@ class ConvertLeetSpeak extends Operation {
 
         this.name = "Convert Leet Speak";
         this.module = "Default";
-        this.description = "Converts to and from Leet Speak";
+        this.description = "Converts to and from Leet Speak.";
         this.infoURL = "https://wikipedia.org/wiki/Leet";
         this.inputType = "string";
         this.outputType = "string";
@@ -39,13 +39,16 @@ class ConvertLeetSpeak extends Operation {
      */
     run(input, args) {
         const direction = args[0];
+
         if (direction === "To Leet Speak") {
-            return input.replace(/[abcdefghijklmnopqrstuvwxyz]/gi, char => {
-                return toLeetMap[char.toLowerCase()] || char;
+            return input.replace(/[a-z]/gi, char => {
+                const leetChar = toLeetMap[char.toLowerCase()] || char;
+                return char === char.toUpperCase() ? leetChar.toUpperCase() : leetChar;
             });
         } else if (direction === "From Leet Speak") {
-            return input.replace(/[48cd3f6h1jklmn0pqr57uvwxyz]/g, char => {
-                return fromLeetMap[char] || char;
+            return input.replace(/[48cd3f6h1jklmn0pqr57uvwxyz]/gi, char => {
+                const normalChar = fromLeetMap[char] || char;
+                return normalChar;
             });
         }
     }
diff --git a/tests/operations/tests/ConvertLeetSpeak.mjs b/tests/operations/tests/ConvertLeetSpeak.mjs
index 198f7e57d2..d344580359 100644
--- a/tests/operations/tests/ConvertLeetSpeak.mjs
+++ b/tests/operations/tests/ConvertLeetSpeak.mjs
@@ -28,6 +28,28 @@ TestRegister.addTests([
                 args: ["From Leet Speak"]
             }
         ]
+    },
+    {
+        name: "Convert to Leet Speak: basic text, keep case",
+        input: "HELLO",
+        expectedOutput: "H3LL0",
+        recipeConfig: [
+            {
+                op: "Convert Leet Speak",
+                args: ["To Leet Speak"]
+            }
+        ]
+    },
+    {
+        name: "Convert from Leet Speak: basic leet, keep case",
+        input: "H3LL0",
+        expectedOutput: "HeLLo",
+        recipeConfig: [
+            {
+                op: "Convert Leet Speak",
+                args: ["From Leet Speak"]
+            }
+        ]
     }
 ]);