diff --git a/cpp/VectorConfig.cpp b/cpp/VectorConfig.cpp
index 338026fa8..c37875c1b 100644
--- a/cpp/VectorConfig.cpp
+++ b/cpp/VectorConfig.cpp
@@ -35,12 +35,6 @@ std::vector<Symbol> VectorConfig::get_names() const {
   return names;
 }
 
-/* ************************************************************************* */
-VectorConfig& VectorConfig::insert(const Symbol& name, const Vector& val) {
-  values.insert(std::make_pair(name,val));
-  return *this;
-}
-
 /* ************************************************************************* */
 void VectorConfig::insert(const VectorConfig& config) {
 	for (const_iterator it = config.begin(); it!=config.end(); it++) {
diff --git a/cpp/VectorConfig.h b/cpp/VectorConfig.h
index d6f6f9ff1..96637d537 100644
--- a/cpp/VectorConfig.h
+++ b/cpp/VectorConfig.h
@@ -40,7 +40,10 @@ namespace gtsam {
     std::vector<Symbol> get_names() const;
 
     /** Insert a value into the configuration with a given index */
-    VectorConfig& insert(const Symbol& name, const Vector& val);
+    inline VectorConfig& insert(const Symbol& name, const Vector& val) {
+      values.insert(std::make_pair(name,val));
+      return *this;
+    }
 
     /** Insert a config into another config */
     void insert(const VectorConfig& config);