diff --git a/cpp/Conditional.h b/cpp/Conditional.h
index 601c30d2c..914809603 100644
--- a/cpp/Conditional.h
+++ b/cpp/Conditional.h
@@ -29,6 +29,11 @@ protected:
 
 public:
 
+	/** empty constructor for serialization */
+	Conditional() :
+		key_("__unitialized__") {
+	}
+
 	/** constructor */
 	Conditional(const std::string& key) :
 		key_(key) {
@@ -37,7 +42,6 @@ public:
 	/* destructor */
 	virtual ~Conditional() {
 	}
-	;
 
 	/** check equality */
 	bool equals(const Conditional& c, double tol = 1e-9) const {
diff --git a/cpp/ConditionalGaussian.h b/cpp/ConditionalGaussian.h
index 2e424b36a..fcfd6afe4 100644
--- a/cpp/ConditionalGaussian.h
+++ b/cpp/ConditionalGaussian.h
@@ -52,7 +52,7 @@ protected:
 public:
 
 	/** default constructor needed for serialization */
-	ConditionalGaussian(): Conditional("__unitialized__") {}
+	ConditionalGaussian(){}
 
 	/** constructor */
 	ConditionalGaussian(const std::string& key) :
diff --git a/cpp/Makefile.am b/cpp/Makefile.am
index 5cb963d00..b43295f22 100644
--- a/cpp/Makefile.am
+++ b/cpp/Makefile.am
@@ -150,7 +150,7 @@ testVSLAMFactor_LDADD = libgtsam.la
 
 
 # The header files will be installed in ~/include/gtsam
-headers = gtsam.h Value.h Testable.h Factor.h Conditional.h LinearFactorSet.h 
+headers = gtsam.h Value.h Testable.h Factor.h Conditional.h SymbolicConditional.h LinearFactorSet.h 
 headers += Point2Prior.h Simulated2DOdometry.h Simulated2DMeasurement.h smallExample.h 
 headers += $(sources:.cpp=.h)
 # templates: 
diff --git a/cpp/SymbolicConditional.h b/cpp/SymbolicConditional.h
index adf6087d3..331669682 100644
--- a/cpp/SymbolicConditional.h
+++ b/cpp/SymbolicConditional.h
@@ -32,6 +32,11 @@ namespace gtsam {
 		/** convenience typename for a shared pointer to this class */
 		typedef boost::shared_ptr<SymbolicConditional> shared_ptr;
 
+		/**
+		 * Empty Constructor to make serialization possible
+		 */
+		SymbolicConditional(){}
+
 		/**
 		 * No parents
 		 */