diff --git a/main.js b/main.js
index f40d155..ac4f963 100644
--- a/main.js
+++ b/main.js
@@ -7,12 +7,16 @@ const is_space = (char) => char === ' ' || char === '\t';
 
 const notation_ok = (token) => {
     token = token.toLowerCase();
-    return (
-        (!isNaN(token.charAt(token.length - 1)) && !isNaN(token)) || // because then all of it should be digits
-        token.endsWith("d") ||
-        token.endsWith("b") ||
-        token.endsWith("h")
-    );
+    const rest = token.substring(0, token.length - 1);
+    
+    if (token.endsWith("h")) {
+        token = `0x${rest}`;
+    } else if (token.endsWith("b")) {
+        token = `0b${rest}`;
+    } else if (token.endsWith("d")) {
+        token = rest;
+    }
+    return !isNaN(token);
 };
 
 const razor = (line) => {