diff --git a/asm.js b/asm.js
index 87ce8fa..6a11618 100644
--- a/asm.js
+++ b/asm.js
@@ -101,7 +101,14 @@ class Parser {
 	}
 
     integer(token) {
-        const x = parseInt(token);
+        let base;
+        switch (token.slice(-1)) {
+        case "b": base = 2; break;
+        case "o": base = 8; break;
+        case "h": base = 16; break;
+        default:  base = 10; break;
+        }
+        const x = parseInt(token, base);
         return Number.isNaN(x) ? null : x;
     }