diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
index 79eb3b5ba28..e019d6e22a9 100644
--- a/gcc/cp/typeck.cc
+++ b/gcc/cp/typeck.cc
@@ -7854,8 +7854,7 @@ cp_build_unary_op (enum tree_code code, tree xarg, bool noconvert,
        if (gnu_vector_type_p (TREE_TYPE (arg)))
      return cp_build_binary_op (input_location, EQ_EXPR, arg,
                     build_zero_cst (TREE_TYPE (arg)), complain);
-      arg = perform_implicit_conversion (boolean_type_node, arg,
-                     complain);
+      arg = contextual_conv_bool (arg, complain);
        if (arg != error_mark_node)
      {
        if (processing_template_decl)
diff --git a/gcc/testsuite/g++.dg/DRs/dr1423.C b/gcc/testsuite/g++.dg/DRs/dr1423.C
index d82baae9985..75bc5e0bc99 100644
--- a/gcc/testsuite/g++.dg/DRs/dr1423.C
+++ b/gcc/testsuite/g++.dg/DRs/dr1423.C
@@ -5,3 +5,4 @@ bool b = nullptr; // { dg-error "converting to .bool. from .std::nullptr_t. requ
  bool b2(nullptr);
  bool b3{nullptr};
  bool b4 = { nullptr }; // { dg-error "converting to .bool. from .std::nullptr_t. requires direct-initialization" }
+bool b5 = !nullptr;