diff --git a/cpp/VectorConfig.cpp b/cpp/VectorConfig.cpp
index 0b802d803..4d02dbc80 100644
--- a/cpp/VectorConfig.cpp
+++ b/cpp/VectorConfig.cpp
@@ -149,6 +149,17 @@ const Vector& VectorConfig::get(const std::string& name) const {
   return it->second;
 }
 
+/* ************************************************************************* */
+Vector& VectorConfig::getReference(const std::string& name) {
+  iterator it = values.find(name);
+  if (it==values.end()) {
+    print();
+    cout << "asked for key " << name << endl;
+    throw(std::invalid_argument("VectorConfig::[] invalid key"));
+  }
+  return it->second;
+}
+
 /* ************************************************************************* */
 void VectorConfig::print(const std::string& name) const {
   odprintf("VectorConfig %s\n", name.c_str());
diff --git a/cpp/VectorConfig.h b/cpp/VectorConfig.h
index 5971582a4..0f0d86446 100644
--- a/cpp/VectorConfig.h
+++ b/cpp/VectorConfig.h
@@ -61,6 +61,9 @@ namespace gtsam {
     /** get a vector in the configuration by name */
     const Vector& get(const std::string& name) const;
 
+    /** get a vector reference by name */
+    Vector& getReference(const std::string& name);
+
     /** operator[] syntax for get */
 		inline const Vector& operator[](const std::string& name) const {
 			return get(name);
diff --git a/cpp/testVectorConfig.cpp b/cpp/testVectorConfig.cpp
index 5077e7a3e..0b5472f91 100644
--- a/cpp/testVectorConfig.cpp
+++ b/cpp/testVectorConfig.cpp
@@ -153,6 +153,15 @@ TEST( VectorConfig, operators) {
 	CHECK(assert_equal(expected2,c-c));
 }
 
+/* ************************************************************************* */
+TEST( VectorConfig, getReference) {
+	VectorConfig c; c.insert("x", Vector_(2, 1.1, 2.2));
+	Vector& cx = c.getReference("x");
+	cx = cx*2.0;
+	VectorConfig expected; expected.insert("x", Vector_(2, 2.2, 4.4));
+	CHECK(assert_equal(expected,c));
+}
+
 /* ************************************************************************* */
 #ifdef HAVE_BOOST_SERIALIZATION
 TEST( VectorConfig, serialize)