diff --git a/include/crucible/cache.h b/include/crucible/cache.h
index 60d2a7f..767b790 100644
--- a/include/crucible/cache.h
+++ b/include/crucible/cache.h
@@ -18,7 +18,7 @@ namespace crucible {
 	public:
 		using Key = tuple<Arguments...>;
 		using Func = function<Return(Arguments...)>;
-		using Time = unsigned;
+		using Time = size_t;
 		using Value = pair<Time, Return>;
 	private:
 		Func		m_fn;
@@ -28,7 +28,7 @@ namespace crucible {
 		size_t		m_max_size;
 		mutex		m_mutex;
 
-		void check_overflow();
+		bool check_overflow();
 	public:
 		LRUCache(Func f = Func(), size_t max_size = 100);
 
@@ -52,21 +52,24 @@ namespace crucible {
 	}
 
 	template <class Return, class... Arguments>
-	void
+	bool
 	LRUCache<Return, Arguments...>::check_overflow()
 	{
-		if (m_map.size() <= m_max_size) return;
-		vector<pair<Key, Time>> map_contents;
-		map_contents.reserve(m_map.size());
-		for (auto i : m_map) {
-			map_contents.push_back(make_pair(i.first, i.second.first));
+		if (m_map.size() <= m_max_size) {
+			return false;
 		}
-		sort(map_contents.begin(), map_contents.end(), [](const pair<Key, Time> &a, const pair<Key, Time> &b) {
+		vector<pair<Key, Time>> key_times;
+		key_times.reserve(m_map.size());
+		for (auto i : m_map) {
+			key_times.push_back(make_pair(i.first, i.second.first));
+		}
+		sort(key_times.begin(), key_times.end(), [](const pair<Key, Time> &a, const pair<Key, Time> &b) {
 			return a.second < b.second;
 		});
-		for (size_t i = 0; i < map_contents.size() / 2; ++i) {
-			m_map.erase(map_contents[i].first);
+		for (size_t i = 0; i < key_times.size() / 2; ++i) {
+			m_map.erase(key_times[i].first);
 		}
+		return true;
 	}
 
 	template <class Return, class... Arguments>
@@ -141,9 +144,14 @@ namespace crucible {
 				// We hold a lock on this key so we are the ones to insert it
 				THROW_CHECK0(runtime_error, inserted);
 
-				// Release key lock and clean out overflow
+				// Release key lock, keep the cache lock
 				key_lock.unlock();
-				check_overflow();
+
+				// Check to see if we have too many items and reduce if so.
+				if (check_overflow()) {
+					// Reset iterator
+					found = m_map.find(k);
+				}
 			}
 		}
 
@@ -207,7 +215,12 @@ namespace crucible {
 
 				// Release key lock and clean out overflow
 				key_lock.unlock();
-				check_overflow();
+
+				// Check to see if we have too many items and reduce if so.
+				if (check_overflow()) {
+					// Reset iterator
+					found = m_map.find(k);
+				}
 			}
 		}