diff --git a/3d-graphics-examples.cabal b/3d-graphics-examples.cabal
--- a/3d-graphics-examples.cabal
+++ b/3d-graphics-examples.cabal
@@ -1,16 +1,16 @@
 Name:          3d-graphics-examples
-Version:       0.0.0.0
+Version:       0.0.0.1
 Cabal-Version: >= 1.8
 Build-Type:    Simple
 License:       BSD3
 License-File:  LICENSE
-Copyright:     © 2006       Matthias Reisner;
-               © 2012, 2013 Wolfgang Jeltsch
+Copyright:     © 2006      Matthias Reisner;
+               © 2012–2015 Wolfgang Jeltsch
 Author:        Matthias Reisner
 Maintainer:    wolfgang@cs.ioc.ee
 Stability:     provisional
 Homepage:      http://darcs.wolfgang.jeltsch.info/haskell/3d-graphics-examples
-Package-URL:   http://hackage.haskell.org/packages/archive/3d-graphics-examples/0.0.0.0/3d-graphics-examples-0.0.0.0.tar.gz
+Package-URL:   http://hackage.haskell.org/packages/archive/3d-graphics-examples/0.0.0.1/3d-graphics-examples-0.0.0.1.tar.gz
 Synopsis:      Examples of 3D graphics programming with OpenGL
 Description:   This package demonstrates how to program simple interactive 3D
                graphics with OpenGL. It contains two programs, which are both
@@ -29,7 +29,7 @@
                who supervised this student project, is now maintaining these
                programs.
 Category:      Graphics, Fractals
-Tested-With:   GHC == 7.6.3
+Tested-With:   GHC == 7.10.1
 
 Source-Repository head
     Type:     darcs
@@ -38,12 +38,23 @@
 Source-Repository this
     Type:     darcs
     Location: http://darcs.wolfgang.jeltsch.info/haskell/3d-graphics-examples/main
-    Tag:      3d-graphics-examples-0.0.0.0
+    Tag:      3d-graphics-examples-0.0.0.1
 
+Executable mountains
+    Build-Depends:  base   >= 3.0 && < 5,
+                    GLUT   >= 2.4 && < 2.8,
+                    OpenGL >= 2.8 && < 2.13,
+                    random >= 1.0 && < 1.1
+    Extensions:     FlexibleContexts
+    Main-Is:        Mountains.hs
+    Other-Modules:  Utilities
+    HS-Source-Dirs: src src/mountains
+
 Executable l-systems
     Build-Depends:  base   >= 3.0 && < 5,
-                    GLUT   >= 2.4 && < 2.6,
-                    OpenGL >= 2.8 && < 2.10
+                    GLUT   >= 2.4 && < 2.8,
+                    OpenGL >= 2.8 && < 2.13
+    Extensions:     FlexibleContexts
     Main-Is:        LSystems.hs
     Other-Modules:  Utilities
                     ConiferLSystem
@@ -53,12 +64,3 @@
                     TreeLSystem
                     Turtle
     HS-Source-Dirs: src src/l-systems
-
-Executable mountains
-    Build-Depends:  base   >= 3.0 && < 5,
-                    GLUT   >= 2.4 && < 2.6,
-                    OpenGL >= 2.8 && < 2.10,
-                    random >= 1.0 && < 1.1
-    Main-Is:        Mountains.hs
-    Other-Modules:  Utilities
-    HS-Source-Dirs: src src/mountains
diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,5 +1,5 @@
-Copyright © 2006       Matthias Reisner
-Copyright © 2012, 2013 Wolfgang Jeltsch
+Copyright © 2006      Matthias Reisner
+Copyright © 2012–2015 Wolfgang Jeltsch
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,
diff --git a/src/Utilities.hs b/src/Utilities.hs
--- a/src/Utilities.hs
+++ b/src/Utilities.hs
@@ -56,6 +56,7 @@
   materialSpecular Back $= Color4 rs gs bs 1.0
   materialShininess Back $= exp
 
+cCyanMaterial :: IO ()
 cCyanMaterial = crMat (0, 0.3, 0.3) (1, 1, 1.0) 5