diff --git a/libcxx/include/__iterator/insert_iterator.h b/libcxx/include/__iterator/insert_iterator.h
--- a/libcxx/include/__iterator/insert_iterator.h
+++ b/libcxx/include/__iterator/insert_iterator.h
@@ -14,6 +14,7 @@
 #include <__iterator/iterator.h>
 #include <__iterator/iterator_traits.h>
 #include <__memory/addressof.h>
+#include <__ranges/access.h>
 #include <__utility/move.h>
 #include <cstddef>
 
@@ -36,8 +37,12 @@
 _LIBCPP_SUPPRESS_DEPRECATED_POP
 protected:
     _Container* container;
-    typename _Container::iterator iter; // FIXME: `ranges::iterator_t<Container>` in C++20 mode
-public:
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_RANGES)
+    ranges::iterator_t<_Container> iter;
+#else
+    typename _Container::iterator iter;
+#endif
+  public:
     typedef output_iterator_tag iterator_category;
     typedef void value_type;
 #if _LIBCPP_STD_VER > 17
@@ -49,8 +54,13 @@
     typedef void reference;
     typedef _Container container_type;
 
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_RANGES)
+    _LIBCPP_INLINE_VISIBILITY constexpr insert_iterator(_Container& __x, ranges::iterator_t<_Container> __i)
+        : container(_VSTD::addressof(__x)), iter(__i) {}
+#else
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator(_Container& __x, typename _Container::iterator __i)
         : container(_VSTD::addressof(__x)), iter(__i) {}
+#endif
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 insert_iterator& operator=(const typename _Container::value_type& __value_)
         {iter = container->insert(iter, __value_); ++iter; return *this;}
 #ifndef _LIBCPP_CXX03_LANG
diff --git a/libcxx/test/std/iterators/predef.iterators/insert.iterators/insert.iterator/cxx20_iter_member.pass.cpp b/libcxx/test/std/iterators/predef.iterators/insert.iterators/insert.iterator/cxx20_iter_member.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/iterators/predef.iterators/insert.iterators/insert.iterator/cxx20_iter_member.pass.cpp
@@ -0,0 +1,42 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+// insert_iterator
+
+#include <cassert>
+#include <iterator>
+
+struct NoIteratorAlias {
+  int data_[3] = {};
+  using value_type = int;
+  int* begin() { return nullptr; }
+  constexpr int* insert(int* pos, int value) {
+    *pos = value;
+    return pos;
+  }
+};
+
+constexpr bool test_no_iterator_alias() {
+  NoIteratorAlias c;
+  auto it = std::insert_iterator<NoIteratorAlias>(c, c.data_);
+  *it++ = 1;
+  *it++ = 2;
+  assert(c.data_[0] == 1);
+  assert(c.data_[1] == 2);
+  assert(c.data_[2] == 0);
+  return true;
+}
+
+int main(int, char**) {
+  test_no_iterator_alias();
+  static_assert(test_no_iterator_alias());
+
+  return 0;
+}