diff --git a/CMakeLists.txt b/CMakeLists.txt
index 34b4f1293c4d8d3f3290725ea991a1a1a098ff52..1f3381c2bf13857d1b2ae1531899d86be24d2ffd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -45,6 +45,9 @@ PKG_CONFIG_APPEND_LIBS("dynamic-graph-python")
 # Search for Boost.
 SEARCH_FOR_BOOST()
 
+# Make sure Boost.Filesystem v2 is used.
+ADD_DEFINITIONS(-DBOOST_FILESYSTEM_VERSION=2)
+
 ADD_SUBDIRECTORY(src)
 ADD_SUBDIRECTORY(include)
 ADD_SUBDIRECTORY(doc)