diff --git a/scripts/bench-gateway-restart.ts b/scripts/bench-gateway-restart.ts
index 7c317d1d3018..a59f9f55391a 100644
--- a/scripts/bench-gateway-restart.ts
+++ b/scripts/bench-gateway-restart.ts
@@ -218,20 +218,29 @@ const GATEWAY_CASES: readonly GatewayBenchCase[] = [
   },
 ] as const;
 
-function parseFlagValue(flag: string): string | undefined {
-  const index = process.argv.indexOf(flag);
-  if (index === -1) {
-    return undefined;
+function readRequiredFlagValue(argv: string[], index: number, flag: string): string {
+  const value = argv[index + 1];
+  if (!value || value.startsWith("-")) {
+    throw new Error(`${flag} requires a value`);
   }
-  return process.argv[index + 1];
+  return value;
 }
 
-function hasFlag(flag: string): boolean {
-  return process.argv.includes(flag);
+function parseFlagValue(argv: string[], flag: string): string | undefined {
+  for (let index = 0; index < argv.length; index += 1) {
+    if (argv[index] === flag) {
+      return readRequiredFlagValue(argv, index, flag);
+    }
+  }
+  return undefined;
 }
 
-function hasHelpFlag(): boolean {
-  return hasFlag("--help") || hasFlag("-h");
+function hasFlag(argv: string[], flag: string): boolean {
+  return argv.includes(flag);
+}
+
+function hasHelpFlag(argv: string[]): boolean {
+  return hasFlag(argv, "--help") || hasFlag(argv, "-h");
 }
 
 function ensureSupportedRestartPlatform(platform: NodeJS.Platform = process.platform): void {
@@ -242,11 +251,12 @@ function ensureSupportedRestartPlatform(platform: NodeJS.Platform = process.plat
   }
 }
 
-function parseRepeatableFlag(flag: string): string[] {
+function parseRepeatableFlag(argv: string[], flag: string): string[] {
   const values: string[] = [];
-  for (let index = 0; index < process.argv.length; index += 1) {
-    if (process.argv[index] === flag && process.argv[index + 1]) {
-      values.push(process.argv[index + 1]);
+  for (let index = 0; index < argv.length; index += 1) {
+    if (argv[index] === flag) {
+      values.push(readRequiredFlagValue(argv, index, flag));
+      index += 1;
     }
   }
   return values;
@@ -296,22 +306,26 @@ function resolveCases(caseIds: string[]): GatewayBenchCase[] {
   });
 }
 
-function parseOptions(): CliOptions {
+function parseOptions(argv: string[] = process.argv.slice(2)): CliOptions {
   return {
-    allowFailures: hasFlag("--allow-failures"),
-    cases: resolveCases(parseRepeatableFlag("--case")),
-    entry: resolveEntry(parseFlagValue("--entry")),
-    json: hasFlag("--json"),
-    output: resolveOutputPath(parseFlagValue("--output")),
+    allowFailures: hasFlag(argv, "--allow-failures"),
+    cases: resolveCases(parseRepeatableFlag(argv, "--case")),
+    entry: resolveEntry(parseFlagValue(argv, "--entry")),
+    json: hasFlag(argv, "--json"),
+    output: resolveOutputPath(parseFlagValue(argv, "--output")),
     postReadyDelayMs: parseNonNegativeInt(
-      parseFlagValue("--post-ready-delay-ms"),
+      parseFlagValue(argv, "--post-ready-delay-ms"),
       DEFAULT_POST_READY_DELAY_MS,
       "--post-ready-delay-ms",
     ),
-    restarts: parsePositiveInt(parseFlagValue("--restarts"), DEFAULT_RESTARTS, "--restarts"),
-    runs: parsePositiveInt(parseFlagValue("--runs"), DEFAULT_RUNS, "--runs"),
-    timeoutMs: parsePositiveInt(parseFlagValue("--timeout-ms"), DEFAULT_TIMEOUT_MS, "--timeout-ms"),
-    warmup: parseNonNegativeInt(parseFlagValue("--warmup"), DEFAULT_WARMUP, "--warmup"),
+    restarts: parsePositiveInt(parseFlagValue(argv, "--restarts"), DEFAULT_RESTARTS, "--restarts"),
+    runs: parsePositiveInt(parseFlagValue(argv, "--runs"), DEFAULT_RUNS, "--runs"),
+    timeoutMs: parsePositiveInt(
+      parseFlagValue(argv, "--timeout-ms"),
+      DEFAULT_TIMEOUT_MS,
+      "--timeout-ms",
+    ),
+    warmup: parseNonNegativeInt(parseFlagValue(argv, "--warmup"), DEFAULT_WARMUP, "--warmup"),
   };
 }
 
@@ -1600,13 +1614,14 @@ function shouldFailBenchmark(results: CaseResult[], options: { allowFailures: bo
 }
 
 async function main() {
-  if (hasHelpFlag()) {
+  const argv = process.argv.slice(2);
+  if (hasHelpFlag(argv)) {
     printUsage();
     return;
   }
 
   ensureSupportedRestartPlatform();
-  const options = parseOptions();
+  const options = parseOptions(argv);
   const results: CaseResult[] = [];
   for (const benchCase of options.cases) {
     results.push(
@@ -1665,6 +1680,7 @@ export const testing = {
   hasInitialReadyLogs,
   hasBenchmarkFailures,
   parseNonNegativeInt,
+  parseOptions,
   parsePositiveInt,
   resolveRestartDeadlineFailure,
   resolveEntry,
diff --git a/scripts/bench-gateway-startup.ts b/scripts/bench-gateway-startup.ts
index af1db1455d7a..218105490494 100644
--- a/scripts/bench-gateway-startup.ts
+++ b/scripts/bench-gateway-startup.ts
@@ -178,27 +178,37 @@ const GATEWAY_CASES: readonly GatewayBenchCase[] = [
   },
 ] as const;
 
-function parseFlagValue(flag: string): string | undefined {
-  const index = process.argv.indexOf(flag);
-  if (index === -1) {
-    return undefined;
+function readRequiredFlagValue(argv: string[], index: number, flag: string): string {
+  const value = argv[index + 1];
+  if (!value || value.startsWith("-")) {
+    throw new Error(`${flag} requires a value`);
   }
-  return process.argv[index + 1];
+  return value;
 }
 
-function hasFlag(flag: string): boolean {
-  return process.argv.includes(flag);
+function parseFlagValue(argv: string[], flag: string): string | undefined {
+  for (let index = 0; index < argv.length; index += 1) {
+    if (argv[index] === flag) {
+      return readRequiredFlagValue(argv, index, flag);
+    }
+  }
+  return undefined;
 }
 
-function hasHelpFlag(): boolean {
-  return hasFlag("--help") || hasFlag("-h");
+function hasFlag(argv: string[], flag: string): boolean {
+  return argv.includes(flag);
 }
 
-function parseRepeatableFlag(flag: string): string[] {
+function hasHelpFlag(argv: string[]): boolean {
+  return hasFlag(argv, "--help") || hasFlag(argv, "-h");
+}
+
+function parseRepeatableFlag(argv: string[], flag: string): string[] {
   const values: string[] = [];
-  for (let index = 0; index < process.argv.length; index += 1) {
-    if (process.argv[index] === flag && process.argv[index + 1]) {
-      values.push(process.argv[index + 1]);
+  for (let index = 0; index < argv.length; index += 1) {
+    if (argv[index] === flag) {
+      values.push(readRequiredFlagValue(argv, index, flag));
+      index += 1;
     }
   }
   return values;
@@ -248,16 +258,20 @@ function resolveCases(caseIds: string[]): GatewayBenchCase[] {
   });
 }
 
-function parseOptions(): CliOptions {
+function parseOptions(argv: string[] = process.argv.slice(2)): CliOptions {
   return {
-    cases: resolveCases(parseRepeatableFlag("--case")),
-    cpuProfDir: parseFlagValue("--cpu-prof-dir"),
-    entry: resolveEntry(parseFlagValue("--entry")),
-    json: hasFlag("--json"),
-    output: resolveOutputPath(parseFlagValue("--output")),
-    runs: parsePositiveInt(parseFlagValue("--runs"), DEFAULT_RUNS, "--runs"),
-    timeoutMs: parsePositiveInt(parseFlagValue("--timeout-ms"), DEFAULT_TIMEOUT_MS, "--timeout-ms"),
-    warmup: parseNonNegativeInt(parseFlagValue("--warmup"), DEFAULT_WARMUP, "--warmup"),
+    cases: resolveCases(parseRepeatableFlag(argv, "--case")),
+    cpuProfDir: parseFlagValue(argv, "--cpu-prof-dir"),
+    entry: resolveEntry(parseFlagValue(argv, "--entry")),
+    json: hasFlag(argv, "--json"),
+    output: resolveOutputPath(parseFlagValue(argv, "--output")),
+    runs: parsePositiveInt(parseFlagValue(argv, "--runs"), DEFAULT_RUNS, "--runs"),
+    timeoutMs: parsePositiveInt(
+      parseFlagValue(argv, "--timeout-ms"),
+      DEFAULT_TIMEOUT_MS,
+      "--timeout-ms",
+    ),
+    warmup: parseNonNegativeInt(parseFlagValue(argv, "--warmup"), DEFAULT_WARMUP, "--warmup"),
   };
 }
 
@@ -1033,12 +1047,13 @@ function printResult(result: CaseResult): void {
 }
 
 async function main() {
-  if (hasHelpFlag()) {
+  const argv = process.argv.slice(2);
+  if (hasHelpFlag(argv)) {
     printUsage();
     return;
   }
 
-  const options = parseOptions();
+  const options = parseOptions(argv);
   if (options.cpuProfDir) {
     mkdirSync(options.cpuProfDir, { recursive: true });
   }
@@ -1085,6 +1100,7 @@ export const testing = {
   classifyProbeErrorKind,
   collectResultFailures,
   collectStartupTrace,
+  parseOptions,
   parseNonNegativeInt,
   parsePositiveInt,
   resolveEntry,
diff --git a/test/scripts/bench-gateway-restart.test.ts b/test/scripts/bench-gateway-restart.test.ts
index 3965c760b9b0..daf02dfec012 100644
--- a/test/scripts/bench-gateway-restart.test.ts
+++ b/test/scripts/bench-gateway-restart.test.ts
@@ -44,9 +44,32 @@ describe("gateway restart benchmark script", () => {
   it("rejects ambiguous benchmark CLI values before spawning Node", () => {
     expect(testing.parsePositiveInt("5", 1, "--restarts")).toBe(5);
     expect(testing.parseNonNegativeInt("0", 1, "--warmup")).toBe(0);
+    expect(
+      testing.parseOptions([
+        "--case",
+        "skipChannelsNoAcpxProbe",
+        "--output",
+        "restart.json",
+        "--allow-failures",
+        "--restarts",
+        "2",
+      ]),
+    ).toMatchObject({
+      allowFailures: true,
+      cases: [{ id: "skipChannelsNoAcpxProbe" }],
+      output: "restart.json",
+      restarts: 2,
+    });
     expect(() => testing.parsePositiveInt("2abc", 1, "--restarts")).toThrow(
       /--restarts must be an integer/u,
     );
+    expect(() => testing.parseOptions(["--output", "--case", "skipChannels"])).toThrow(
+      "--output requires a value",
+    );
+    expect(() => testing.parseOptions(["--case"])).toThrow("--case requires a value");
+    expect(() => testing.parseOptions(["--restarts", "--runs", "1"])).toThrow(
+      "--restarts requires a value",
+    );
     expect(() => testing.resolveEntry("--inspect")).toThrow(/must be a file path/u);
   });
 
diff --git a/test/scripts/bench-gateway-startup.test.ts b/test/scripts/bench-gateway-startup.test.ts
index 4e6d9f5c3650..067a9a525905 100644
--- a/test/scripts/bench-gateway-startup.test.ts
+++ b/test/scripts/bench-gateway-startup.test.ts
@@ -54,9 +54,32 @@ describe("gateway startup benchmark script", () => {
   it("rejects ambiguous benchmark CLI values before spawning Node", () => {
     expect(testing.parsePositiveInt("5", 1, "--runs")).toBe(5);
     expect(testing.parseNonNegativeInt("0", 1, "--warmup")).toBe(0);
+    expect(
+      testing.parseOptions([
+        "--case",
+        "default",
+        "--output",
+        "startup.json",
+        "--json",
+        "--runs",
+        "2",
+      ]),
+    ).toMatchObject({
+      cases: [{ id: "default" }],
+      json: true,
+      output: "startup.json",
+      runs: 2,
+    });
     expect(() => testing.parsePositiveInt("2abc", 1, "--runs")).toThrow(
       /--runs must be an integer/u,
     );
+    expect(() => testing.parseOptions(["--output", "--case", "default"])).toThrow(
+      "--output requires a value",
+    );
+    expect(() => testing.parseOptions(["--case"])).toThrow("--case requires a value");
+    expect(() => testing.parseOptions(["--runs", "--warmup", "0"])).toThrow(
+      "--runs requires a value",
+    );
     expect(() => testing.resolveEntry("--inspect")).toThrow(/must be a file path/u);
   });