diff --git a/EIPS/eip-663.md b/EIPS/eip-663.md
index 9c8b126479bf88..f8b9306c0a51bc 100644
--- a/EIPS/eip-663.md
+++ b/EIPS/eip-663.md
@@ -39,11 +39,13 @@ If the code is valid EOF1, the following execution rules apply:
  1. These instructions are followed by an 8-bit immediate value, which we call `imm`, and can have a value of 0 to 255. We introduce the variable `n` which equals to `imm + 17`.
 
  2. For `DUPN`:
+
    - If the current stack height is less than `n`, then a stack underflow exception is issued.
    - If the current stack height is at the limit (1024), a stack overflow exception is issued.
    - Otherwise the `n`'th stack item is duplicated at the top of the stack. (*Note: We use 1-based indexing here.*)
 
  3. For `SWAPN`:
+
    - If the current stack height is less than `n + 1`, then a stack underflow exception is issued.
    - Otherwise the `n + 1`th stack item is swapped with the top stack item.