diff --git a/libcxx/test/std/utilities/format/format.functions/locale-specific_form.pass.cpp b/libcxx/test/std/utilities/format/format.functions/locale-specific_form.pass.cpp
--- a/libcxx/test/std/utilities/format/format.functions/locale-specific_form.pass.cpp
+++ b/libcxx/test/std/utilities/format/format.functions/locale-specific_form.pass.cpp
@@ -9,9 +9,7 @@
 // UNSUPPORTED: libcpp-no-concepts
 // UNSUPPORTED: libcpp-has-no-localization
 // UNSUPPORTED: libcpp-has-no-incomplete-format
-
-// TODO(mordante): Investigate these localization/format failures since updating the Docker image in CI
-// UNSUPPORTED: stdlib=libc++
+// XFAIL: LIBCXX-DEBUG-FIXME
 
 // REQUIRES: locale.en_US.UTF-8