diff --git a/include/cista/containers/vector.h b/include/cista/containers/vector.h
index e65ee6d..09cfb43 100644
--- a/include/cista/containers/vector.h
+++ b/include/cista/containers/vector.h
@@ -217,13 +217,13 @@ struct basic_vector {
     return std::rotate(begin() + old_offset, begin() + old_size, end());
   }
 
-  template <typename El, typename Size = std::size_t>
-  constexpr T* insert(T* it, Size const count, El const& value) {
+  template <typename El>
+  constexpr T* insert(T* it, size_type const count, El const& value) {
     auto const old_offset = std::distance(begin(), it);
     auto const old_size = used_size_;
 
     reserve(used_size_ + count);
-    for (auto i = Size{0U}; i < count; ++i) {
+    for (auto i = size_type{0U}; i < count; ++i) {
       new (el_ + used_size_) T{value};
       ++used_size_;
     }