diff --git a/test/built-ins/Temporal/Duration/prototype/round/roundto-invalid-string.js b/test/built-ins/Temporal/Duration/prototype/round/roundto-invalid-string.js
new file mode 100644
index 0000000000..3e5a43386b
--- /dev/null
+++ b/test/built-ins/Temporal/Duration/prototype/round/roundto-invalid-string.js
@@ -0,0 +1,27 @@
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.duration.prototype.round
+description: RangeError thrown when smallestUnit option not one of the allowed string values
+features: [Temporal]
+---*/
+
+const duration = new Temporal.Duration(0, 0, 0, 0, 12, 34, 56, 123, 987, 500);
+const badValues = [
+  "era",
+  "eraYear",
+  "millisecond\0",
+  "mill\u0131second",
+  "SECOND",
+  "eras",
+  "eraYears",
+  "milliseconds\0",
+  "mill\u0131seconds",
+  "SECONDS",
+  "other string",
+];
+for (const smallestUnit of badValues) {
+  assert.throws(RangeError, () => duration.round(smallestUnit),
+    `"${smallestUnit}" is not a valid value for smallest unit`);
+}
diff --git a/test/built-ins/Temporal/Duration/prototype/round/smallestunit-disallowed-units-string.js b/test/built-ins/Temporal/Duration/prototype/round/smallestunit-disallowed-units-string.js
deleted file mode 100644
index f2cf0b0f01..0000000000
--- a/test/built-ins/Temporal/Duration/prototype/round/smallestunit-disallowed-units-string.js
+++ /dev/null
@@ -1,26 +0,0 @@
-// Copyright (C) 2021 Igalia, S.L. All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-esid: sec-temporal.duration.prototype.round
-description: Specifically disallowed units for the smallestUnit option
-features: [Temporal, arrow-function]
----*/
-
-const instance = new Temporal.Duration(0, 0, 0, 4, 5, 6, 7, 987, 654, 321);
-const invalidUnits = [
-  "era",
-  "eras",
-];
-invalidUnits.forEach((smallestUnit) => {
-  assert.throws(
-    RangeError,
-    () => instance.round({ smallestUnit }),
-    `{ smallestUnit: "${smallestUnit}" } should not be allowed as an argument to round`
-  );
-  assert.throws(
-    RangeError,
-    () => instance.round(smallestUnit),
-    `"${smallestUnit}" should not be allowed as an argument to round`
-  );
-});
diff --git a/test/built-ins/Temporal/Instant/prototype/round/roundto-invalid-string.js b/test/built-ins/Temporal/Instant/prototype/round/roundto-invalid-string.js
new file mode 100644
index 0000000000..db76bcd23f
--- /dev/null
+++ b/test/built-ins/Temporal/Instant/prototype/round/roundto-invalid-string.js
@@ -0,0 +1,35 @@
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.instant.prototype.round
+description: RangeError thrown when smallestUnit option not one of the allowed string values
+features: [Temporal]
+---*/
+
+const instant = new Temporal.Instant(1_000_000_000_123_987_500n);
+const badValues = [
+  "era",
+  "eraYear",
+  "year",
+  "month",
+  "week",
+  "day",
+  "millisecond\0",
+  "mill\u0131second",
+  "SECOND",
+  "eras",
+  "eraYears",
+  "years",
+  "months",
+  "weeks",
+  "days",
+  "milliseconds\0",
+  "mill\u0131seconds",
+  "SECONDS",
+  "other string",
+];
+for (const smallestUnit of badValues) {
+  assert.throws(RangeError, () => instant.round(smallestUnit),
+    `"${smallestUnit}" is not a valid value for smallest unit`);
+}
diff --git a/test/built-ins/Temporal/Instant/prototype/round/smallestunit-disallowed-units.js b/test/built-ins/Temporal/Instant/prototype/round/smallestunit-disallowed-units.js
deleted file mode 100644
index 2d7dcb1d5f..0000000000
--- a/test/built-ins/Temporal/Instant/prototype/round/smallestunit-disallowed-units.js
+++ /dev/null
@@ -1,34 +0,0 @@
-// Copyright (C) 2021 Igalia, S.L. All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-esid: sec-temporal.instant.prototype.round
-description: Specifically disallowed units for the smallestUnit option
-features: [Temporal, arrow-function]
----*/
-
-const instance = new Temporal.Instant(1_000_000_000_987_654_321n);
-const invalidUnits = [
-  "era",
-  "eras",
-  "year",
-  "month",
-  "week",
-  "years",
-  "months",
-  "weeks",
-  "day",
-  "days",
-];
-invalidUnits.forEach((smallestUnit) => {
-  assert.throws(
-    RangeError,
-    () => instance.round({ smallestUnit }),
-    `{ smallestUnit: "${smallestUnit}" } should not be allowed as an argument to round`
-  );
-  assert.throws(
-    RangeError,
-    () => instance.round(smallestUnit),
-    `"${smallestUnit}" should not be allowed as an argument to round`
-  );
-});
diff --git a/test/built-ins/Temporal/PlainDateTime/prototype/round/roundto-invalid-string.js b/test/built-ins/Temporal/PlainDateTime/prototype/round/roundto-invalid-string.js
new file mode 100644
index 0000000000..184d11731c
--- /dev/null
+++ b/test/built-ins/Temporal/PlainDateTime/prototype/round/roundto-invalid-string.js
@@ -0,0 +1,33 @@
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindatetime.prototype.round
+description: RangeError thrown when smallestUnit option not one of the allowed string values
+features: [Temporal]
+---*/
+
+const datetime = new Temporal.PlainDateTime(2000, 5, 2, 12, 34, 56, 123, 987, 500);
+const badValues = [
+  "era",
+  "eraYear",
+  "year",
+  "month",
+  "week",
+  "millisecond\0",
+  "mill\u0131second",
+  "SECOND",
+  "eras",
+  "eraYears",
+  "years",
+  "months",
+  "weeks",
+  "milliseconds\0",
+  "mill\u0131seconds",
+  "SECONDS",
+  "other string",
+];
+for (const smallestUnit of badValues) {
+  assert.throws(RangeError, () => datetime.round(smallestUnit),
+    `"${smallestUnit}" is not a valid value for smallest unit`);
+}
diff --git a/test/built-ins/Temporal/PlainDateTime/prototype/round/smallestunit-disallowed-units.js b/test/built-ins/Temporal/PlainDateTime/prototype/round/smallestunit-disallowed-units.js
deleted file mode 100644
index cd85d00ae1..0000000000
--- a/test/built-ins/Temporal/PlainDateTime/prototype/round/smallestunit-disallowed-units.js
+++ /dev/null
@@ -1,32 +0,0 @@
-// Copyright (C) 2021 Igalia, S.L. All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-esid: sec-temporal.plaindatetime.prototype.round
-description: Specifically disallowed units for the smallestUnit option
-features: [Temporal, arrow-function]
----*/
-
-const instance = new Temporal.PlainDateTime(2000, 5, 2, 12, 34, 56, 789, 999, 999);
-const invalidUnits = [
-  "era",
-  "eras",
-  "year",
-  "month",
-  "week",
-  "years",
-  "months",
-  "weeks",
-];
-invalidUnits.forEach((smallestUnit) => {
-  assert.throws(
-    RangeError,
-    () => instance.round({ smallestUnit }),
-    `{ smallestUnit: "${smallestUnit}" } should not be allowed as an argument to round`
-  );
-  assert.throws(
-    RangeError,
-    () => instance.round(smallestUnit),
-    `"${smallestUnit}" should not be allowed as an argument to round`
-  );
-});
diff --git a/test/built-ins/Temporal/PlainTime/prototype/round/roundto-invalid-string.js b/test/built-ins/Temporal/PlainTime/prototype/round/roundto-invalid-string.js
new file mode 100644
index 0000000000..53a665f951
--- /dev/null
+++ b/test/built-ins/Temporal/PlainTime/prototype/round/roundto-invalid-string.js
@@ -0,0 +1,35 @@
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaintime.prototype.round
+description: RangeError thrown when smallestUnit option not one of the allowed string values
+features: [Temporal]
+---*/
+
+const time = new Temporal.PlainTime(12, 34, 56, 123, 987, 500);
+const badValues = [
+  "era",
+  "eraYear",
+  "year",
+  "month",
+  "week",
+  "day",
+  "millisecond\0",
+  "mill\u0131second",
+  "SECOND",
+  "eras",
+  "eraYears",
+  "years",
+  "months",
+  "weeks",
+  "days",
+  "milliseconds\0",
+  "mill\u0131seconds",
+  "SECONDS",
+  "other string",
+];
+for (const smallestUnit of badValues) {
+  assert.throws(RangeError, () => time.round(smallestUnit),
+    `"${smallestUnit}" is not a valid value for smallest unit`);
+}
diff --git a/test/built-ins/Temporal/PlainTime/prototype/round/smallestunit-disallowed-units.js b/test/built-ins/Temporal/PlainTime/prototype/round/smallestunit-disallowed-units.js
deleted file mode 100644
index 1a9da4e74a..0000000000
--- a/test/built-ins/Temporal/PlainTime/prototype/round/smallestunit-disallowed-units.js
+++ /dev/null
@@ -1,34 +0,0 @@
-// Copyright (C) 2021 Igalia, S.L. All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-esid: sec-temporal.plaintime.prototype.round
-description: Specifically disallowed units for the smallestUnit option
-features: [Temporal, arrow-function]
----*/
-
-const instance = new Temporal.PlainTime(12, 34, 56, 789, 999, 999);
-const invalidUnits = [
-  "era",
-  "eras",
-  "year",
-  "month",
-  "week",
-  "years",
-  "months",
-  "weeks",
-  "day",
-  "days",
-];
-invalidUnits.forEach((smallestUnit) => {
-  assert.throws(
-    RangeError,
-    () => instance.round({ smallestUnit }),
-    `{ smallestUnit: "${smallestUnit}" } should not be allowed as an argument to round`
-  );
-  assert.throws(
-    RangeError,
-    () => instance.round(smallestUnit),
-    `"${smallestUnit}" should not be allowed as an argument to round`
-  );
-});
diff --git a/test/built-ins/Temporal/ZonedDateTime/prototype/round/roundto-invalid-string.js b/test/built-ins/Temporal/ZonedDateTime/prototype/round/roundto-invalid-string.js
new file mode 100644
index 0000000000..9ce1a9e17d
--- /dev/null
+++ b/test/built-ins/Temporal/ZonedDateTime/prototype/round/roundto-invalid-string.js
@@ -0,0 +1,33 @@
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.zoneddatetime.prototype.round
+description: RangeError thrown when smallestUnit option not one of the allowed string values
+features: [Temporal]
+---*/
+
+const datetime = new Temporal.ZonedDateTime(1_000_000_000_123_987_500n, "UTC");
+const badValues = [
+  "era",
+  "eraYear",
+  "year",
+  "month",
+  "week",
+  "millisecond\0",
+  "mill\u0131second",
+  "SECOND",
+  "eras",
+  "eraYears",
+  "years",
+  "months",
+  "weeks",
+  "milliseconds\0",
+  "mill\u0131seconds",
+  "SECONDS",
+  "other string",
+];
+for (const smallestUnit of badValues) {
+  assert.throws(RangeError, () => datetime.round(smallestUnit),
+    `"${smallestUnit}" is not a valid value for smallest unit`);
+}
diff --git a/test/built-ins/Temporal/ZonedDateTime/prototype/round/smallestunit-disallowed-units.js b/test/built-ins/Temporal/ZonedDateTime/prototype/round/smallestunit-disallowed-units.js
deleted file mode 100644
index f89f4c6752..0000000000
--- a/test/built-ins/Temporal/ZonedDateTime/prototype/round/smallestunit-disallowed-units.js
+++ /dev/null
@@ -1,32 +0,0 @@
-// Copyright (C) 2021 Igalia, S.L. All rights reserved.
-// This code is governed by the BSD license found in the LICENSE file.
-
-/*---
-esid: sec-temporal.zoneddatetime.prototype.round
-description: Specifically disallowed units for the smallestUnit option
-features: [Temporal, arrow-function]
----*/
-
-const instance = new Temporal.ZonedDateTime(1_000_000_000_987_654_321n, "UTC");
-const invalidUnits = [
-  "era",
-  "eras",
-  "year",
-  "month",
-  "week",
-  "years",
-  "months",
-  "weeks",
-];
-invalidUnits.forEach((smallestUnit) => {
-  assert.throws(
-    RangeError,
-    () => instance.round({ smallestUnit }),
-    `{ smallestUnit: "${smallestUnit}" } should not be allowed as an argument to round`
-  );
-  assert.throws(
-    RangeError,
-    () => instance.round(smallestUnit),
-    `"${smallestUnit}" should not be allowed as an argument to round`
-  );
-});