diff --git a/ostd/unordered_map.hh b/ostd/unordered_map.hh
index 5ce1a55..f537f7b 100644
--- a/ostd/unordered_map.hh
+++ b/ostd/unordered_map.hh
@@ -30,7 +30,6 @@ struct ranged_traits<std::unordered_map<K, T> const> {
 
 template<typename K, typename T, typename R>
 inline std::unordered_map<K, T> make_unordered_map(R range) {
-    /* TODO: specialize for contiguous ranges and matching value types */
     std::unordered_map<K, T> ret;
     for (; !range.empty(); range.pop_front()) {
         ret.emplace(range.front());
@@ -42,11 +41,11 @@ template<typename R>
 inline std::unordered_map<
     typename RangeValue<R>::first_type,
     typename RangeValue<R>::second_type
-> make_unordered_map(R range) {
+> make_unordered_map(R &&range) {
     return make_unordered_map<
         typename RangeValue<R>::first_type,
         typename RangeValue<R>::second_type
-    >(std::move(range));
+    >(std::forward<R>(range));
 }
 
 } /* namespace ostd */
diff --git a/ostd/vector.hh b/ostd/vector.hh
index 143cd8b..a1766bf 100644
--- a/ostd/vector.hh
+++ b/ostd/vector.hh
@@ -37,8 +37,8 @@ inline std::vector<T> make_vector(R range) {
 }
 
 template<typename R>
-inline std::vector<RangeValue<R>> make_vector(R range) {
-    return make_vector<RangeValue<R>>(std::move(range));
+inline std::vector<RangeValue<R>> make_vector(R &&range) {
+    return make_vector<RangeValue<R>>(std::forward<R>(range));
 }
 
 } /* namespace ostd */