diff --git a/src/standalone/runtime.spec.ts b/src/standalone/runtime.spec.ts
new file mode 100644
index 00000000000..f59c65f6d2f
--- /dev/null
+++ b/src/standalone/runtime.spec.ts
@@ -0,0 +1,77 @@
+import { expect } from "chai";
+import * as childProcess from "child_process";
+import * as sinon from "sinon";
+
+import * as runtime from "../../standalone/runtime";
+
+describe("standalone runtime", () => {
+  let sandbox: sinon.SinonSandbox;
+
+  beforeEach(() => {
+    sandbox = sinon.createSandbox();
+  });
+
+  afterEach(() => {
+    delete (globalThis as any).appendToPath;
+    delete (globalThis as any).getSafeCrossPlatformPath;
+    sandbox.restore();
+  });
+
+  describe("normalizeShellScriptArgs", () => {
+    it("strips npm's -- sentinel after -c", () => {
+      expect(runtime.normalizeShellScriptArgs(["-c", "--", "npm install"])).to.deep.equal([
+        "npm install",
+      ]);
+    });
+
+    it("preserves a leading -- when it is not the -c sentinel", () => {
+      expect(runtime.normalizeShellScriptArgs(["--", "npm install"])).to.deep.equal([
+        "--",
+        "npm install",
+      ]);
+    });
+
+    it("preserves arguments after the command string", () => {
+      expect(
+        runtime.normalizeShellScriptArgs(["-c", "--", "node ./script.js", "--flag", "value"]),
+      ).to.deep.equal(["node ./script.js", "--flag", "value"]);
+    });
+  });
+
+  describe("Script_ShellJS", () => {
+    it("uses normalized shell args when invoking node commands", async () => {
+      const originalArgv = process.argv;
+      const fakeChild = { on: sandbox.stub().returnsThis() };
+      const forkStub = sandbox.stub(childProcess, "fork").returns(fakeChild as any);
+      const spawnStub = sandbox.stub(childProcess, "spawn").returns(fakeChild as any);
+
+      (globalThis as any).appendToPath = sandbox.stub();
+      (globalThis as any).getSafeCrossPlatformPath = sandbox.stub().resolvesArg(1);
+
+      process.argv = [
+        process.execPath,
+        "shell.js",
+        "-c",
+        "--",
+        `${process.execPath} ./script.js --flag value`,
+      ];
+
+      try {
+        await runtime.Script_ShellJS();
+      } finally {
+        process.argv = originalArgv;
+      }
+
+      expect(forkStub).to.have.been.calledOnceWithExactly(
+        "./script.js",
+        ["--flag", "value"],
+        {
+          env: process.env,
+          cwd: process.cwd(),
+          stdio: "inherit",
+        },
+      );
+      expect(spawnStub).not.to.have.been.called;
+    });
+  });
+});
diff --git a/standalone/firepit.js b/standalone/firepit.js
index f7927e1869e..a68b25ad3a0 100644
--- a/standalone/firepit.js
+++ b/standalone/firepit.js
@@ -669,7 +669,7 @@ async function createRuntimeBinaries() {
 node "${FindTool("npm/bin/npm-cli")[0]}" ${npmArgs.join(" ")}  %*`,
 
     /* Runtime scripts */
-    "shell.js": `${appendToPath.toString()}\n${getSafeCrossPlatformPath.toString()}\n(${runtime.Script_ShellJS.toString()})()`,
+    "shell.js": `${appendToPath.toString()}\n${getSafeCrossPlatformPath.toString()}\nconst normalizeShellScriptArgs = ${runtime.normalizeShellScriptArgs.toString()};\n(${runtime.Script_ShellJS.toString()})()`,
     "node.js": `(${runtime.Script_NodeJS.toString()})()`,
 
     /* Config files */
diff --git a/standalone/runtime.js b/standalone/runtime.js
index 36dd52aa9ab..38ded5fba21 100644
--- a/standalone/runtime.js
+++ b/standalone/runtime.js
@@ -57,6 +57,23 @@ exports.Script_NodeJS = function() {
     });
 };
 
+function normalizeShellScriptArgs(args) {
+  args = [...args];
+
+  const index = args.indexOf("-c");
+  if (index !== -1) {
+    args.splice(index, 1);
+
+    if (args[index] === "--") {
+      args.splice(index, 1);
+    }
+  }
+
+  return args;
+}
+
+exports.normalizeShellScriptArgs = normalizeShellScriptArgs;
+
 /*
   -------------------------------------
   "sh" Command
@@ -74,18 +91,13 @@ exports.Script_ShellJS = async function() {
   const path = require("path");
   const child_process = require("child_process");
   const isWin = process.platform === "win32";
-  const args = process.argv.slice(2);
+  const args = normalizeShellScriptArgs(process.argv.slice(2));
 
   appendToPath(isWin, [
     __dirname,
     path.join(process.cwd(), "node_modules/.bin")
   ]);
 
-  let index;
-  if ((index = args.indexOf("-c")) !== -1) {
-    args.splice(index, 1);
-  }
-
   args[0] = args[0].replace(process.execPath, "node");
   let [cmdRuntime, cmdScript, ...otherArgs] = args[0].split(" ");