diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTime.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTime.cpp
index 648ad11a33..ac25bb0276 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTime.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTime.cpp
@@ -282,7 +282,7 @@ ThrowCompletionOr<ZonedDateTime*> create_temporal_zoned_date_time(VM& vm, BigInt
 }
 
 // 6.5.4 TemporalZonedDateTimeToString ( zonedDateTime, precision, showCalendar, showTimeZone, showOffset [ , increment, unit, roundingMode ] ), https://tc39.es/proposal-temporal/#sec-temporal-temporalzoneddatetimetostring
-ThrowCompletionOr<DeprecatedString> temporal_zoned_date_time_to_string(VM& vm, ZonedDateTime& zoned_date_time, Variant<StringView, u8> const& precision, StringView show_calendar, StringView show_time_zone, StringView show_offset, Optional<u64> increment, Optional<StringView> unit, Optional<StringView> rounding_mode)
+ThrowCompletionOr<String> temporal_zoned_date_time_to_string(VM& vm, ZonedDateTime& zoned_date_time, Variant<StringView, u8> const& precision, StringView show_calendar, StringView show_time_zone, StringView show_offset, Optional<u64> increment, Optional<StringView> unit, Optional<StringView> rounding_mode)
 {
     // 1. If increment is not present, set increment to 1.
     if (!increment.has_value())
@@ -330,12 +330,12 @@ ThrowCompletionOr<DeprecatedString> temporal_zoned_date_time_to_string(VM& vm, Z
         offset_string = MUST_OR_THROW_OOM(format_iso_time_zone_offset_string(vm, offset_ns));
     }
 
-    DeprecatedString time_zone_string;
+    String time_zone_string;
 
     // 12. If showTimeZone is "never", then
     if (show_time_zone == "never"sv) {
         // a. Let timeZoneString be the empty String.
-        time_zone_string = DeprecatedString::empty();
+        time_zone_string = {};
     }
     // 13. Else,
     else {
@@ -346,14 +346,14 @@ ThrowCompletionOr<DeprecatedString> temporal_zoned_date_time_to_string(VM& vm, Z
         auto flag = show_time_zone == "critical"sv ? "!"sv : ""sv;
 
         // c. Let timeZoneString be the string-concatenation of the code unit 0x005B (LEFT SQUARE BRACKET), flag, timeZoneID, and the code unit 0x005D (RIGHT SQUARE BRACKET).
-        time_zone_string = DeprecatedString::formatted("[{}{}]", flag, time_zone_id);
+        time_zone_string = TRY_OR_THROW_OOM(vm, String::formatted("[{}{}]", flag, time_zone_id));
     }
 
     // 14. Let calendarString be ? MaybeFormatCalendarAnnotation(zonedDateTime.[[Calendar]], showCalendar).
     auto calendar_string = TRY(maybe_format_calendar_annotation(vm, &zoned_date_time.calendar(), show_calendar));
 
     // 15. Return the string-concatenation of dateTimeString, offsetString, timeZoneString, and calendarString.
-    return DeprecatedString::formatted("{}{}{}{}", date_time_string, offset_string, time_zone_string, calendar_string);
+    return TRY_OR_THROW_OOM(vm, String::formatted("{}{}{}{}", date_time_string, offset_string, time_zone_string, calendar_string));
 }
 
 // 6.5.5 AddZonedDateTime ( epochNanoseconds, timeZone, calendar, years, months, weeks, days, hours, minutes, seconds, milliseconds, microseconds, nanoseconds [ , options ] ), https://tc39.es/proposal-temporal/#sec-temporal-addzoneddatetime
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTime.h b/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTime.h
index 0c70fe8732..d384c7c3d6 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTime.h
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTime.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
  */
@@ -55,7 +55,7 @@ enum class MatchBehavior {
 ThrowCompletionOr<BigInt const*> interpret_iso_date_time_offset(VM&, i32 year, u8 month, u8 day, u8 hour, u8 minute, u8 second, u16 millisecond, u16 microsecond, u16 nanosecond, OffsetBehavior offset_behavior, double offset_nanoseconds, Value time_zone, StringView disambiguation, StringView offset_option, MatchBehavior match_behavior);
 ThrowCompletionOr<ZonedDateTime*> to_temporal_zoned_date_time(VM&, Value item, Object const* options = nullptr);
 ThrowCompletionOr<ZonedDateTime*> create_temporal_zoned_date_time(VM&, BigInt const& epoch_nanoseconds, Object& time_zone, Object& calendar, FunctionObject const* new_target = nullptr);
-ThrowCompletionOr<DeprecatedString> temporal_zoned_date_time_to_string(VM&, ZonedDateTime& zoned_date_time, Variant<StringView, u8> const& precision, StringView show_calendar, StringView show_time_zone, StringView show_offset, Optional<u64> increment = {}, Optional<StringView> unit = {}, Optional<StringView> rounding_mode = {});
+ThrowCompletionOr<String> temporal_zoned_date_time_to_string(VM&, ZonedDateTime& zoned_date_time, Variant<StringView, u8> const& precision, StringView show_calendar, StringView show_time_zone, StringView show_offset, Optional<u64> increment = {}, Optional<StringView> unit = {}, Optional<StringView> rounding_mode = {});
 ThrowCompletionOr<BigInt*> add_zoned_date_time(VM&, BigInt const& epoch_nanoseconds, Value time_zone, Object& calendar, double years, double months, double weeks, double days, double hours, double minutes, double seconds, double milliseconds, double microseconds, double nanoseconds, Object* options = nullptr);
 ThrowCompletionOr<DurationRecord> difference_zoned_date_time(VM&, BigInt const& nanoseconds1, BigInt const& nanoseconds2, Object& time_zone, Object& calendar, StringView largest_unit, Object const& options);
 ThrowCompletionOr<NanosecondsToDaysResult> nanoseconds_to_days(VM&, Crypto::SignedBigInteger nanoseconds, Value relative_to);