diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.cpp
index 8eee6d9796..f38d9d0df5 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainMonthDay.cpp
@@ -187,8 +187,8 @@ ThrowCompletionOr<String> temporal_month_day_to_string(GlobalObject& global_obje
     // 6. Let calendarID be ? ToString(monthDay.[[Calendar]]).
     auto calendar_id = TRY(Value(&month_day.calendar()).to_string(global_object));
 
-    // 7. If calendarID is not "iso8601", then
-    if (calendar_id != "iso8601"sv) {
+    // 7. If showCalendar is "always" or if calendarID is not "iso8601", then
+    if (show_calendar == "always"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 = String::formatted("{}-{}", pad_iso_year(month_day.iso_year()), result);
diff --git a/Userland/Libraries/LibJS/Runtime/Temporal/PlainYearMonth.cpp b/Userland/Libraries/LibJS/Runtime/Temporal/PlainYearMonth.cpp
index 487f6a27c9..f122784630 100644
--- a/Userland/Libraries/LibJS/Runtime/Temporal/PlainYearMonth.cpp
+++ b/Userland/Libraries/LibJS/Runtime/Temporal/PlainYearMonth.cpp
@@ -245,8 +245,8 @@ ThrowCompletionOr<String> temporal_year_month_to_string(GlobalObject& global_obj
     // 6. Let calendarID be ? ToString(yearMonth.[[Calendar]]).
     auto calendar_id = TRY(Value(&year_month.calendar()).to_string(global_object));
 
-    // 7. If calendarID is not "iso8601", then
-    if (calendar_id != "iso8601") {
+    // 7. If showCalendar is "always" or if calendarID is not "iso8601", then
+    if (show_calendar == "always"sv || calendar_id != "iso8601") {
         // a. Let day be yearMonth.[[ISODay]] formatted as a two-digit decimal number, padded to the left with a zero if necessary.
         // b. Set result to the string-concatenation of result, the code unit 0x002D (HYPHEN-MINUS), and day.
         result = String::formatted("{}-{:02}", result, year_month.iso_day());
diff --git a/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainMonthDay/PlainMonthDay.prototype.toString.js b/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainMonthDay/PlainMonthDay.prototype.toString.js
index 8a1c4b1da2..fa70d2e4fa 100644
--- a/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainMonthDay/PlainMonthDay.prototype.toString.js
+++ b/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainMonthDay/PlainMonthDay.prototype.toString.js
@@ -9,7 +9,7 @@ describe("correct behavior", () => {
         plainMonthDay = new Temporal.PlainMonthDay(7, 6);
         expect(plainMonthDay.toString()).toBe("07-06");
         expect(plainMonthDay.toString({ calendarName: "auto" })).toBe("07-06");
-        expect(plainMonthDay.toString({ calendarName: "always" })).toBe("07-06[u-ca=iso8601]");
+        expect(plainMonthDay.toString({ calendarName: "always" })).toBe("1972-07-06[u-ca=iso8601]");
         expect(plainMonthDay.toString({ calendarName: "never" })).toBe("07-06");
 
         plainMonthDay = new Temporal.PlainMonthDay(7, 6, { toString: () => "foo" }, 2021);
diff --git a/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainYearMonth/PlainYearMonth.prototype.toString.js b/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainYearMonth/PlainYearMonth.prototype.toString.js
index ef7b6433cb..2be37729d9 100644
--- a/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainYearMonth/PlainYearMonth.prototype.toString.js
+++ b/Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainYearMonth/PlainYearMonth.prototype.toString.js
@@ -9,7 +9,9 @@ describe("correct behavior", () => {
         plainYearMonth = new Temporal.PlainYearMonth(2021, 7);
         expect(plainYearMonth.toString()).toBe("2021-07");
         expect(plainYearMonth.toString({ calendarName: "auto" })).toBe("2021-07");
-        expect(plainYearMonth.toString({ calendarName: "always" })).toBe("2021-07[u-ca=iso8601]");
+        expect(plainYearMonth.toString({ calendarName: "always" })).toBe(
+            "2021-07-01[u-ca=iso8601]"
+        );
         expect(plainYearMonth.toString({ calendarName: "never" })).toBe("2021-07");
 
         plainYearMonth = new Temporal.PlainYearMonth(2021, 7, { toString: () => "foo" }, 6);