diff --git a/lib/dir.js b/lib/dir.js
index df04cd08..923fdd65 100644
--- a/lib/dir.js
+++ b/lib/dir.js
@@ -49,7 +49,6 @@ class DirFetcher extends Fetcher {
         pkg: mani,
         event: 'prepare',
         path: this.resolved,
-        stdioString: true,
         stdio,
         banner,
         env: {
diff --git a/lib/util/npm.js b/lib/util/npm.js
index c444d788..a3005c25 100644
--- a/lib/util/npm.js
+++ b/lib/util/npm.js
@@ -10,5 +10,5 @@ module.exports = (npmBin, npmCommand, cwd, env, extra) => {
   // in temp directories.  this lets us link previously-seen repos that
   // are also being prepared.
 
-  return spawn(cmd, args, { cwd, stdioString: true, env }, extra)
+  return spawn(cmd, args, { cwd, env }, extra)
 }
diff --git a/package.json b/package.json
index 93e7cb03..b4b6d6db 100644
--- a/package.json
+++ b/package.json
@@ -47,7 +47,7 @@
     "@npmcli/git": "^4.0.0",
     "@npmcli/installed-package-contents": "^2.0.1",
     "@npmcli/promise-spawn": "^6.0.1",
-    "@npmcli/run-script": "^5.0.0",
+    "@npmcli/run-script": "^6.0.0",
     "cacache": "^17.0.0",
     "fs-minipass": "^2.1.0",
     "minipass": "^3.1.6",
diff --git a/tap-snapshots/test/util/npm.js.test.cjs b/tap-snapshots/test/util/npm.js.test.cjs
index ed109cd4..b5dedcb1 100644
--- a/tap-snapshots/test/util/npm.js.test.cjs
+++ b/tap-snapshots/test/util/npm.js.test.cjs
@@ -16,7 +16,7 @@ Object {
   "message": "oopsie",
   "signal": undefined,
   "stderr": "",
-  "stdout": "[\\"{NODE}\\",[\\"/path/to/npm/bin/npm-cli.js\\",\\"flerb\\"],{\\"cwd\\":\\"/cwd\\",\\"stdioString\\":true,\\"env\\":{\\"environmental\\":\\"variables\\"}}]",
+  "stdout": "[\\"{NODE}\\",[\\"/path/to/npm/bin/npm-cli.js\\",\\"flerb\\"],{\\"cwd\\":\\"/cwd\\",\\"env\\":{\\"environmental\\":\\"variables\\"}}]",
 }
 `
 
@@ -30,6 +30,6 @@ Object {
   "message": "oopsie",
   "signal": undefined,
   "stderr": "",
-  "stdout": "[\\"/path/to/npm\\",[\\"flerb\\"],{\\"cwd\\":\\"/cwd\\",\\"stdioString\\":true,\\"env\\":{\\"environmental\\":\\"variables\\"}}]",
+  "stdout": "[\\"/path/to/npm\\",[\\"flerb\\"],{\\"cwd\\":\\"/cwd\\",\\"env\\":{\\"environmental\\":\\"variables\\"}}]",
 }
 `