diff --git a/.gitignore b/.gitignore
index 55a8686..b2c2064 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 *.hi
 *~
 Mandelbulb
+hglmandel
diff --git a/01_Introduction/hglmandel.lhs b/01_Introduction/hglmandel.lhs
index a12a1c0..2a966c3 100644
--- a/01_Introduction/hglmandel.lhs
+++ b/01_Introduction/hglmandel.lhs
@@ -20,7 +20,7 @@ And the second part more focused on OpenGL and content.
 
 For efficiency reason, I will not use the default Haskell `Complex` data type.
 
-> newtype Complex = C (Float,Float) deriving (Show,Eq)
+> data Complex = C (Float,Float) deriving (Show,Eq)
 
 
 > instance Num Complex where