diff --git a/asm.js b/asm.js
index 97f62b7..3a2c7e4 100644
--- a/asm.js
+++ b/asm.js
@@ -316,7 +316,7 @@ class Parser {
         if (opcode)
             return { type: Action.APPEND, opcode };
         const literal = this.integer(token);
-        if (literal)
+        if (literal != null)
             return { type: Action.APPEND, literal };
 
         return { type: Action.SYMBOL, symbol: token };