diff --git a/Assembler/GUIDE.txt b/Assembler/GUIDE.txt
index ccb59b84cf7..8b0a3836ef5 100644
--- a/Assembler/GUIDE.txt
+++ b/Assembler/GUIDE.txt
@@ -67,7 +67,7 @@ int 0x80
 
 ```
 
-**Important: The arithmetic commands (add, sub) works only with registers or constans. 
+**Important: The arithmetic commands (add, sub) works only with registers or constants. 
 Therefore we must use the register ebx as a placeholder, above.**