diff --git a/cpp/SymbolicFactor.h b/cpp/SymbolicFactor.h
index f9ebb1317..921ccbe9c 100644
--- a/cpp/SymbolicFactor.h
+++ b/cpp/SymbolicFactor.h
@@ -33,7 +33,7 @@ namespace gtsam {
 		SymbolicFactor(const boost::shared_ptr<SymbolicConditional>& c);
 
 		/** Constructor from a list of keys */
-		SymbolicFactor(std::list<std::string> keys) :
+		SymbolicFactor(const Ordering& keys) :
 			keys_(keys) {
 		}
 
diff --git a/cpp/gtsam.h b/cpp/gtsam.h
index 6be6041d5..e32ba1032 100644
--- a/cpp/gtsam.h
+++ b/cpp/gtsam.h
@@ -5,6 +5,8 @@ class Ordering {
 };
 
 class SymbolicFactor{
+	SymbolicFactor(const Ordering& keys);
+	void print(string s) const;
 };
 
 class VectorConfig {