diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.cpp
index ead6405019..b88012f5e1 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021-2022, Linus Groh <linusg@serenityos.org>
+ * Copyright (c) 2021-2023, Linus Groh <linusg@serenityos.org>
  * Copyright (c) 2021, Luke Wilde <lukew@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
@@ -174,7 +174,7 @@ ThrowCompletionOr<PlainMonthDay*> create_temporal_month_day(VM& vm, u8 iso_month
 }
 
 // 10.5.3 TemporalMonthDayToString ( monthDay, showCalendar ), https://tc39.es/proposal-temporal/#sec-temporal-temporalmonthdaytostring
-ThrowCompletionOr<DeprecatedString> temporal_month_day_to_string(VM& vm, PlainMonthDay& month_day, StringView show_calendar)
+ThrowCompletionOr<String> temporal_month_day_to_string(VM& vm, PlainMonthDay& month_day, StringView show_calendar)
 {
     // 1. Assert: Type(monthDay) is Object.
     // 2. Assert: monthDay has an [[InitializedTemporalMonthDay]] internal slot.
@@ -182,16 +182,16 @@ ThrowCompletionOr<DeprecatedString> temporal_month_day_to_string(VM& vm, PlainMo
     // 3. Let month be ToZeroPaddedDecimalString(temporalDate.[[ISOMonth]], 2).
     // 4. Let day be ToZeroPaddedDecimalString(temporalDate.[[ISODay]], 2).
     // 5. Let result be the string-concatenation of month, the code unit 0x002D (HYPHEN-MINUS), and day.
-    auto result = DeprecatedString::formatted("{:02}-{:02}", month_day.iso_month(), month_day.iso_day());
+    auto result = TRY_OR_THROW_OOM(vm, String::formatted("{:02}-{:02}", month_day.iso_month(), month_day.iso_day()));
 
     // 6. Let calendarID be ? ToString(monthDay.[[Calendar]]).
-    auto calendar_id = TRY(Value(&month_day.calendar()).to_deprecated_string(vm));
+    auto calendar_id = TRY(Value(&month_day.calendar()).to_string(vm));
 
     // 7. If showCalendar is one of "always" or "critical", or if calendarID is not "iso8601", then
     if (show_calendar.is_one_of("always"sv, "critical"sv) || calendar_id != "iso8601"sv) {
         // a. Let year be ! PadISOYear(monthDay.[[ISOYear]]).
         // b. Set result to the string-concatenation of year, the code unit 0x002D (HYPHEN-MINUS), and result.
-        result = DeprecatedString::formatted("{}-{}", pad_iso_year(month_day.iso_year()), result);
+        result = TRY_OR_THROW_OOM(vm, String::formatted("{}-{}", pad_iso_year(month_day.iso_year()), result));
     }
 
     // 8. Let calendarString be ! FormatCalendarAnnotation(calendarID, showCalendar).
@@ -199,7 +199,7 @@ ThrowCompletionOr<DeprecatedString> temporal_month_day_to_string(VM& vm, PlainMo
 
     // 9. Set result to the string-concatenation of result and calendarString.
     // 10. Return result.
-    return DeprecatedString::formatted("{}{}", result, calendar_string);
+    return TRY_OR_THROW_OOM(vm, String::formatted("{}{}", result, calendar_string));
 }
 
 }
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.h b/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.h
index 3d38f13298..5a8628a1da 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.h
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021-2022, Linus Groh <linusg@serenityos.org>
+ * Copyright (c) 2021-2023, Linus Groh <linusg@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -42,6 +42,6 @@ struct ISOMonthDay {
 
 ThrowCompletionOr<PlainMonthDay*> to_temporal_month_day(VM&, Value item, Object const* options = nullptr);
 ThrowCompletionOr<PlainMonthDay*> create_temporal_month_day(VM&, u8 iso_month, u8 iso_day, Object& calendar, i32 reference_iso_year, FunctionObject const* new_target = nullptr);
-ThrowCompletionOr<DeprecatedString> temporal_month_day_to_string(VM&, PlainMonthDay&, StringView show_calendar);
+ThrowCompletionOr<String> temporal_month_day_to_string(VM&, PlainMonthDay&, StringView show_calendar);
 
 }