diff --git a/cpp/BayesNet-inl.h b/cpp/BayesNet-inl.h
index 2f7af67a4..0680bc703 100644
--- a/cpp/BayesNet-inl.h
+++ b/cpp/BayesNet-inl.h
@@ -4,6 +4,8 @@
  * @author Frank Dellaert
  */
 
+#pragma once
+
 #include <iostream>
 #include <fstream>
 #include <boost/foreach.hpp>
diff --git a/cpp/BayesTree-inl.h b/cpp/BayesTree-inl.h
index 5a80a3eae..f243da941 100644
--- a/cpp/BayesTree-inl.h
+++ b/cpp/BayesTree-inl.h
@@ -6,6 +6,8 @@
  * @author  Viorela Ila
  */
 
+#pragma once
+
 #include <iostream>
 
 #include <boost/foreach.hpp>
diff --git a/cpp/JunctionTree-inl.h b/cpp/JunctionTree-inl.h
index c30831d87..ca807476d 100644
--- a/cpp/JunctionTree-inl.h
+++ b/cpp/JunctionTree-inl.h
@@ -6,6 +6,8 @@
  *  Description: the junction tree
  */
 
+#pragma once
+
 #include <boost/tuple/tuple.hpp>
 #include <boost/foreach.hpp>
 #include <boost/optional.hpp>
diff --git a/cpp/inference-inl.h b/cpp/inference-inl.h
index c2fd62f96..0ec66d98b 100644
--- a/cpp/inference-inl.h
+++ b/cpp/inference-inl.h
@@ -4,6 +4,8 @@
  * @author Frank Dellaert
  */
 
+#pragma once
+
 #include "inference.h"
 #include "FactorGraph-inl.h"
 #include "BayesNet-inl.h"
diff --git a/cpp/testGaussianFactorGraph.cpp b/cpp/testGaussianFactorGraph.cpp
index 568a91cfb..9f10f5188 100644
--- a/cpp/testGaussianFactorGraph.cpp
+++ b/cpp/testGaussianFactorGraph.cpp
@@ -25,7 +25,7 @@ using namespace boost::assign;
 #include "GaussianBayesNet.h"
 #include "numericalDerivative.h"
 #include "SymbolicFactorGraph.h"
-#include "BayesTree.h"
+#include "BayesTree-inl.h"
 #include "inference-inl.h" // needed for eliminate and marginals