diff --git a/src/xtd.core/include/xtd/collections/object_model/read_only_collection.h b/src/xtd.core/include/xtd/collections/object_model/read_only_collection.h
index 03875ca26ec..4319e0d9918 100644
--- a/src/xtd.core/include/xtd/collections/object_model/read_only_collection.h
+++ b/src/xtd.core/include/xtd/collections/object_model/read_only_collection.h
@@ -93,9 +93,9 @@ namespace xtd {
         /// @brief Represents the const pointer of list value type.
         using const_pointer = const value_type*;
         /// @brief Represents the iterator of list value type.
-        using iterator = generic::icollection<type_t>::iterator;
+        using iterator = typename generic::icollection<type_t>::iterator;
         /// @brief Represents the const iterator of list value type.
-        using const_iterator = generic::icollection<type_t>::const_iterator;
+        using const_iterator = typename generic::icollection<type_t>::const_iterator;
         /// @}
         
         /// @name Public Fields