diff --git a/trunk/INSTALL b/trunk/INSTALL
index 17aab05b8..0deb56950 100644
--- a/trunk/INSTALL
+++ b/trunk/INSTALL
@@ -125,6 +125,16 @@ If you are in that case and assuming you have a standard path for gcc et g++ 4.7
 
 > cmake .. -DSMP=true -DCMAKE_C_COMPILER=/usr/bin/gcc-4.7 -DCMAKE_CXX_COMPILER=/usr/bin/g++-4.7
 
+------------------------------------------------------------------------------------------
+2.2 PEO MODULE
+------------------------------------------------------------------------------------------
+
+WARNING : The PEO module requires libXML 2 and a MPI implementation such as MPICH2.
+
+To enable the compilation of the PEO module, just add -DPEO=true to CMake :
+
+> cmake .. -DPEO=true
+
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 3. DOCUMENTATION
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