diff --git a/gui/INSTALL.txt b/gui/INSTALL.txt
index df1d931..37d959b 100644
--- a/gui/INSTALL.txt
+++ b/gui/INSTALL.txt
@@ -33,6 +33,13 @@ language. Therefore, the GUI requires the following two items:
   Scyther does not support Python 3. You are therefore recommended to
   choose the latest production release of Python 2, e.g., Python 2.7.
 
+  Mac OS X:
+  	If the package yields an error when you try to install it,
+  	please use the following, in the directory where you downloaded
+  	it:
+  	
+  	 $ sudo installer -pkg graphviz-2.34.0.pkg -target /
+
 
 3. wxPython libraries.
 
@@ -53,6 +60,11 @@ language. Therefore, the GUI requires the following two items:
   Mac OS X:
   	http://downloads.sourceforge.net/wxpython/wxPython2.8-osx-unicode-2.8.12.1-universal-py2.7.dmg
 
+	Note that this package is in an old format and you will probably
+	get a warning "Package is damaged". This can be resolved by:
+  	
+  	 $ sudo installer -pkg /Volume/.../wxPython2.8-osx-unicode-universal-py2.7.pkg/ -target /
+
   Ubuntu/Debian Linux:
   	http://wiki.wxpython.org/InstallingOnUbuntuOrDebian
 
@@ -68,4 +80,9 @@ Start Scyther by executing the file
 
 in the directory where you found this file.
 
+  Mac OS X:
+  
+    Right-click the file 'scyther-gui.py' and select "Open with" and
+    then "Python Launcher".
+
 
diff --git a/src/compile.txt b/src/compile.txt
index d472837..45440cc 100644
--- a/src/compile.txt
+++ b/src/compile.txt
@@ -4,11 +4,24 @@ Requirements expressed as Ubuntu packages where [name][location]
 
 Needed:
 	
-  gcc
-  	If you don't know what this is, please stop reading.
-  cmake
+  [gcc]
+  	The C compiler.
+  	Note that the current default C compiler on Mac OS X, "clang",
+  	will not work. The reason is that Scyther uses nested function
+  	definitions, which are not supported by clang.
+
+  [flex]
+  [bison]
+  	Two tools for the generation of parsers.
+
+  [build-essential]
+  	This meta-package includes several development tools used by
+  	Scyther.
+
+  [cmake]
 	A Makefile generator, available on almost any platform.
 
+
 For cross-compilation (Windows):
 
   [mingw32][universe]