diff --git a/scripts/lib/clean-linux-hopper-runtime.mjs b/scripts/lib/clean-linux-hopper-runtime.mjs
index 27a306fce..206cba53a 100644
--- a/scripts/lib/clean-linux-hopper-runtime.mjs
+++ b/scripts/lib/clean-linux-hopper-runtime.mjs
@@ -1,8 +1,5 @@
-import { execFile } from "node:child_process";
-import { promisify } from "node:util";
-import { readdir, stat } from "node:fs/promises";
-
-const execFileAsync = promisify(execFile);
+import { readFile, readdir, stat } from "node:fs/promises";
+import { basename } from "node:path";
 
 /**
  * Observe leftover demo processes on a dedicated clean Linux runner, including
@@ -17,9 +14,6 @@ export const assertCleanLinuxHopperRuntime = async (
       : [process.env.HOPPER_LAUNCHER_PATH]),
   ],
 ) => {
-  const { stdout } = await execFileAsync("ps", ["-ax", "-o", "command="]);
-  if (/\/opt\/hopper\/bin\/Hopper|\bXvfb\b|hopper-demo-x11\.py/u.test(stdout))
-    throw new Error("Clean Linux runner retained a Hopper demo process");
   const launchers = [];
   for (const path of launcherPaths) {
     try {
@@ -28,18 +22,34 @@ export const assertCleanLinuxHopperRuntime = async (
       if (error?.code !== "ENOENT") throw error;
     }
   }
-  if (launchers.length === 0) return;
   // /proc exposes the executed file even when argv[0] names a removed symlink.
   // Compare file identity, not a display path or a process name.
   let inspectionError;
   for (const entry of await readdir("/proc", { withFileTypes: true })) {
     if (!entry.isDirectory() || !/^\d+$/u.test(entry.name)) continue;
-    let executable;
+    let retainedRuntime;
     try {
-      executable = await stat(`/proc/${entry.name}/exe`, { bigint: true });
+      // procfs preserves argument boundaries. A caller merely mentioning a
+      // runtime in its script text or other arguments is not that runtime.
+      const arguments_ = (
+        await readFile(`/proc/${entry.name}/cmdline`, "utf8")
+      ).split("\0");
+      retainedRuntime =
+        arguments_[0] === "/opt/hopper/bin/Hopper" ||
+        basename(arguments_[0] ?? "") === "Xvfb" ||
+        (basename(arguments_[0] ?? "") === "python3" &&
+          basename(arguments_[1] ?? "") === "hopper-demo-x11.py");
+      if (!retainedRuntime && launchers.length > 0) {
+        const executable = await stat(`/proc/${entry.name}/exe`, {
+          bigint: true,
+        });
+        retainedRuntime = launchers.some(
+          ({ dev, ino }) => dev === executable.dev && ino === executable.ino,
+        );
+      }
     } catch (error) {
       if (error?.code === "ENOENT" || error?.code === "ESRCH") continue;
-      // Other users' executables may be unreadable. The setup lane launches
+      // Other users' process facts may be unreadable. The setup lane launches
       // providers as the caller; unreadable caller-owned processes fail closed.
       if (error?.code === "EACCES") {
         const owner = await stat(`/proc/${entry.name}`).catch((cause) => {
@@ -53,11 +63,7 @@ export const assertCleanLinuxHopperRuntime = async (
       inspectionError ??= error;
       continue;
     }
-    if (
-      launchers.some(
-        ({ dev, ino }) => dev === executable.dev && ino === executable.ino,
-      )
-    )
+    if (retainedRuntime)
       throw new Error("Clean Linux runner retained a Hopper demo process");
   }
   if (inspectionError !== undefined) throw inspectionError;
diff --git a/scripts/lib/real-hopper-search.d.mts b/scripts/lib/real-hopper-search.d.mts
index e64031652..82cfad325 100644
--- a/scripts/lib/real-hopper-search.d.mts
+++ b/scripts/lib/real-hopper-search.d.mts
@@ -1,3 +1,7 @@
+import type { z } from "zod";
+
+import type { analysisStringSchema } from "../../src/domain/hopperValues.js";
+
 type VerifierCall = (
   name: string,
   arguments_?: Record<string, unknown>,
@@ -25,6 +29,3 @@ export function verifyHopperStringObjects(
   }[];
   readonly displayEscapesExcludedFromMatching: true;
 }>;
-import type { z } from "zod";
-
-import type { analysisStringSchema } from "../../src/domain/hopperValues.js";
diff --git a/tests/process-global/cleanLinuxHopperRuntime.test.ts b/tests/boundary/process/cleanLinuxHopperRuntime.test.ts
similarity index 65%
rename from tests/process-global/cleanLinuxHopperRuntime.test.ts
rename to tests/boundary/process/cleanLinuxHopperRuntime.test.ts
index d356f5abf..b41b163a1 100644
--- a/tests/process-global/cleanLinuxHopperRuntime.test.ts
+++ b/tests/boundary/process/cleanLinuxHopperRuntime.test.ts
@@ -1,18 +1,78 @@
 import { execFile } from "node:child_process";
 import { randomUUID } from "node:crypto";
-import { chmod, copyFile, readFile, symlink, unlink } from "node:fs/promises";
+import {
+  chmod,
+  copyFile,
+  readFile,
+  symlink,
+  unlink,
+  writeFile,
+} from "node:fs/promises";
 import { join } from "node:path";
 import { promisify } from "node:util";
 
 import { expect, it } from "vitest";
 
-import { assertCleanLinuxHopperRuntime } from "../../scripts/lib/clean-linux-hopper-runtime.mjs";
-import { completeVerifierRun } from "../../scripts/lib/verifier-run.mjs";
-import { cleanupOwnedProcessGroup } from "../../src/process/ProcessOwnership.js";
-import { createTestTempDirectory } from "../fixtures/temporaryDirectory.js";
+import { assertCleanLinuxHopperRuntime } from "../../../scripts/lib/clean-linux-hopper-runtime.mjs";
+import { completeVerifierRun } from "../../../scripts/lib/verifier-run.mjs";
+import { cleanupOwnedProcessGroup } from "../../../src/process/ProcessOwnership.js";
+import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
 
 const execFileAsync = promisify(execFile);
 
+it.runIf(process.platform === "linux")(
+  "does not treat runtime names in another process's arguments as a runtime",
+  async () => {
+    const observer = new URL(
+      "../../../scripts/lib/clean-linux-hopper-runtime.mjs",
+      import.meta.url,
+    ).href;
+    const code = `
+      const { assertCleanLinuxHopperRuntime } = await import(${JSON.stringify(observer)});
+      await assertCleanLinuxHopperRuntime([]);
+      console.log('clean');
+    `;
+    const { stdout } = await execFileAsync(
+      process.execPath,
+      [
+        "--input-type=module",
+        "-e",
+        code,
+        "Xvfb",
+        "/opt/hopper/bin/Hopper",
+        "hopper-demo-x11.py",
+      ],
+      { timeout: 10_000 },
+    );
+    expect(stdout.trim()).toBe("clean");
+  },
+);
+
+it.runIf(process.platform === "linux")(
+  "distinguishes an ordinary Node script with the helper's filename",
+  async () => {
+    const directory = await createTestTempDirectory("rea-runtime-arguments-");
+    const script = join(directory, "hopper-demo-x11.py");
+    const observer = new URL(
+      "../../../scripts/lib/clean-linux-hopper-runtime.mjs",
+      import.meta.url,
+    ).href;
+    await writeFile(
+      script,
+      `
+      import(${JSON.stringify(observer)}).then(async ({ assertCleanLinuxHopperRuntime }) => {
+        await assertCleanLinuxHopperRuntime([]);
+        console.log('clean');
+      });
+    `,
+    );
+    const { stdout } = await execFileAsync(process.execPath, [script], {
+      timeout: 10_000,
+    });
+    expect(stdout.trim()).toBe("clean");
+  },
+);
+
 it
   .runIf(process.platform === "linux")
   .each(["demo helper", "alternate launcher"])(