diff --git a/cpp/LinearFactorGraph.cpp b/cpp/LinearFactorGraph.cpp
index dc803bb56..6558c746e 100644
--- a/cpp/LinearFactorGraph.cpp
+++ b/cpp/LinearFactorGraph.cpp
@@ -12,7 +12,6 @@
 
 #include <colamd/colamd.h>
 
-#include "GaussianBayesNet.h"
 #include "FactorGraph-inl.h"
 #include "LinearFactorGraph.h"
 #include "LinearFactorSet.h"
diff --git a/cpp/LinearFactorGraph.h b/cpp/LinearFactorGraph.h
index 33fe6f82d..e37a17fab 100644
--- a/cpp/LinearFactorGraph.h
+++ b/cpp/LinearFactorGraph.h
@@ -15,11 +15,11 @@
 #include <boost/shared_ptr.hpp>
 #include "FactorGraph.h"
 #include "LinearFactor.h"
+#include "GaussianBayesNet.h" // needed for MATLAB toolbox !!
 
 namespace gtsam {
 
 	class Ordering;
-	class GaussianBayesNet;
 
   /**
    * A Linear Factor Graph is a factor graph where all factors are Gaussian, i.e.