diff --git a/app.py b/app.py
index 6cf7423..9ad1943 100644
--- a/app.py
+++ b/app.py
@@ -35,6 +35,24 @@ PROHIBITED_WORDS = {
     'git', 'shag', 'minge', 'nonce', 'plonker', 'pillock'
 }
 
+LEET_MAP = str.maketrans({
+    "@": "a",
+    "4": "a",
+    "8": "b",
+    "3": "e",
+    "6": "g",
+    "9": "g",
+    "1": "i",
+    "!": "i",
+    "|": "l",
+    "0": "o",
+    "$": "s",
+    "5": "s",
+    "7": "t",
+    "+": "t",
+    "2": "z",
+})
+
 api = Blueprint("api", __name__, url_prefix="/api")
 
 
@@ -45,7 +63,8 @@ def _get_client_ip() -> str:
 
 def _contains_prohibited_word(text: str) -> bool:
     lower = text.lower()
-    return any(w in lower for w in PROHIBITED_WORDS)
+    normalized = lower.translate(LEET_MAP)
+    return any(w in lower or w in normalized for w in PROHIBITED_WORDS)
 
 
 def _get_discord_session() -> requests.Session: