diff --git a/README.md b/README.md
index f0ca895..b89d3e5 100644
--- a/README.md
+++ b/README.md
@@ -35,6 +35,6 @@ IMPORTANT: your solution should not make use of arrays or matrices of numbers. I
 ## Compiling and Running
 
 ```
-ghc -02 -Wall Spiral.hs -o spiral
+ghc -O2 -Wall Spiral.hs -o spiral
 ./spiral
 ```