diff --git a/core/include/prometheus/family.h b/core/include/prometheus/family.h
index aa946832..f36e3ec6 100644
--- a/core/include/prometheus/family.h
+++ b/core/include/prometheus/family.h
@@ -109,7 +109,9 @@ class PROMETHEUS_CPP_CORE_EXPORT Family : public Collectable {
   /// labels already exists - the already existing dimensional data.
   template <typename... Args>
   T& Add(const std::map<std::string, std::string>& labels, Args&&... args) {
-    return Add(labels, detail::make_unique<T>(args...));
+    metrics_iterator iter = FindMetric(labels);
+    if (iter->second) return *(iter->second);
+    return Add(iter, detail::make_unique<T>(args...));
   }
 
   /// \brief Remove the given dimensional data.
@@ -145,9 +147,11 @@ class PROMETHEUS_CPP_CORE_EXPORT Family : public Collectable {
   const std::map<std::string, std::string> constant_labels_;
   mutable std::mutex mutex_;
 
+  using metrics_iterator = typename std::unordered_map<std::size_t, std::unique_ptr<T>>::iterator;
+
   ClientMetric CollectMetric(std::size_t hash, T* metric) const;
-  T& Add(const std::map<std::string, std::string>& labels,
-         std::unique_ptr<T> object);
+  T& Add(metrics_iterator hint, std::unique_ptr<T> object);
+  metrics_iterator FindMetric(const std::map<std::string, std::string>& labels);
 };
 
 }  // namespace prometheus
diff --git a/core/src/family.cc b/core/src/family.cc
index 83631abc..969dc737 100644
--- a/core/src/family.cc
+++ b/core/src/family.cc
@@ -15,8 +15,8 @@ Family<T>::Family(const std::string& name, const std::string& help,
 }
 
 template <typename T>
-T& Family<T>::Add(const std::map<std::string, std::string>& labels,
-                  std::unique_ptr<T> object) {
+typename Family<T>::metrics_iterator
+Family<T>::FindMetric(const std::map<std::string, std::string>& labels) {
   auto hash = detail::hash_labels(labels);
   std::lock_guard<std::mutex> lock{mutex_};
   auto metrics_iter = metrics_.find(hash);
@@ -28,7 +28,7 @@ T& Family<T>::Add(const std::map<std::string, std::string>& labels,
     const auto& old_labels = labels_iter->second;
     assert(labels == old_labels);
 #endif
-    return *metrics_iter->second;
+    return metrics_iter;
   } else {
 #ifndef NDEBUG
     for (auto& label_pair : labels) {
@@ -37,14 +37,25 @@ T& Family<T>::Add(const std::map<std::string, std::string>& labels,
     }
 #endif
 
-    auto metric = metrics_.insert(std::make_pair(hash, std::move(object)));
+    auto metric = metrics_.insert(std::make_pair(hash, nullptr));
     assert(metric.second);
     labels_.insert({hash, labels});
-    labels_reverse_lookup_.insert({metric.first->second.get(), hash});
-    return *(metric.first->second);
+    return metric.first;
   }
 }
 
+template <typename T>
+T& Family<T>::Add(metrics_iterator hint, std::unique_ptr<T> object) {
+  std::lock_guard<std::mutex> lock{mutex_};
+  auto hash = hint->first;
+  assert(metrics_.find(hash) == hint);
+  if (! hint->second) {
+    labels_reverse_lookup_.insert({object.get(), hash});
+    hint->second.swap(object);
+  }
+  return *(hint->second);
+}
+
 template <typename T>
 void Family<T>::Remove(T* metric) {
   std::lock_guard<std::mutex> lock{mutex_};