diff --git a/03-bootsector-memory/boot_sect_memory_org.asm b/03-bootsector-memory/boot_sect_memory_org.asm
index de5193c..6400843 100644
--- a/03-bootsector-memory/boot_sect_memory_org.asm
+++ b/03-bootsector-memory/boot_sect_memory_org.asm
@@ -40,7 +40,7 @@ jmp $ ; infinite loop
 the_secret:
     ; ASCII code 0x58 ('X') is stored just before the zero-padding.
     ; On this code that is at byte 0x2d (check it out using 'xxd file.bin')
-    db "X"
+    db 'X'
 
 ; zero padding and magic bios number
 times 510-($-$$) db 0