Index: test/std/containers/sequences/vector/vector.cons/construct_iter_iter_alloc.pass.cpp
===================================================================
--- test/std/containers/sequences/vector/vector.cons/construct_iter_iter_alloc.pass.cpp
+++ test/std/containers/sequences/vector/vector.cons/construct_iter_iter_alloc.pass.cpp
@@ -40,6 +40,9 @@
 {
     implicit_conv_allocator(void*) {}
     implicit_conv_allocator(const implicit_conv_allocator&) = default;
+
+    template <class U>
+    implicit_conv_allocator(implicit_conv_allocator<U>) {}
 };
 
 #endif