diff --git a/gtsam/linear/VectorValues.cpp b/gtsam/linear/VectorValues.cpp
index 664fcf3b7..33c62cfb6 100644
--- a/gtsam/linear/VectorValues.cpp
+++ b/gtsam/linear/VectorValues.cpp
@@ -66,6 +66,18 @@ namespace gtsam {
     return result;
   }
 
+  /* ************************************************************************* */
+  VectorValues::iterator VectorValues::insert(const std::pair<Key, Vector>& key_value) {
+    // Note that here we accept a pair with a reference to the Vector, but the Vector is copied as
+    // it is inserted into the values_ map.
+    std::pair<iterator, bool> result = values_.insert(key_value);
+    if(!result.second)
+      throw std::invalid_argument(
+      "Requested to insert variable '" + DefaultKeyFormatter(key_value.first)
+      + "' already in this VectorValues.");
+    return result.first;
+  }
+
   /* ************************************************************************* */
   void VectorValues::update(const VectorValues& values)
   {
diff --git a/gtsam/linear/VectorValues.h b/gtsam/linear/VectorValues.h
index 968fc1adb..d04d9faac 100644
--- a/gtsam/linear/VectorValues.h
+++ b/gtsam/linear/VectorValues.h
@@ -181,23 +181,14 @@ namespace gtsam {
      * @param value The vector to be inserted.
      * @param j The index with which the value will be associated. */
     iterator insert(Key j, const Vector& value) {
-      return insert(std::make_pair(j, value)); // Note only passing a reference to the Vector
+      return insert(std::make_pair(j, value));
     }
 
     /** Insert a vector \c value with key \c j.  Throws an invalid_argument exception if the key \c
      *  j is already used.
      * @param value The vector to be inserted.
      * @param j The index with which the value will be associated. */
-    iterator insert(const std::pair<Key, Vector>& key_value) {
-      // Note that here we accept a pair with a reference to the Vector, but the Vector is copied as
-      // it is inserted into the values_ map.
-      std::pair<iterator, bool> result = values_.insert(key_value);
-      if(!result.second)
-        throw std::invalid_argument(
-        "Requested to insert variable '" + DefaultKeyFormatter(key_value.first)
-        + "' already in this VectorValues.");
-      return result.first;
-    }
+    iterator insert(const std::pair<Key, Vector>& key_value);
 
     /** Insert all values from \c values.  Throws an invalid_argument exception if any keys to be
      *  inserted are already used. */