diff --git a/packages/shell/tool-pwsh-persistent/tests/loader-composition.spec.ts b/packages/shell/tool-pwsh-persistent/tests/loader-composition.spec.ts
index 58b05082d0..729d9f8073 100644
--- a/packages/shell/tool-pwsh-persistent/tests/loader-composition.spec.ts
+++ b/packages/shell/tool-pwsh-persistent/tests/loader-composition.spec.ts
@@ -95,11 +95,19 @@ describe.skipIf(!hasPwsh)('persistent pwsh through a real cordis.yml Loader comp
       '    idleSilenceMs: 300',
       '    handoffGraceMs: 300',
       '    scrollbackLines: 20000',
-      '    timeoutMs: 60000',
+      // The first call pays the full pwsh cold-start latency (spawn + .NET +
+      // PSReadLine + Defender) inside the tool deadline; a 60s bound on the
+      // fully loaded self-hosted Windows pool is exceeded often enough to
+      // reset the session mid-test (2026-09-01, two runs ~62s each). 300s
+      // matches the dsh-tool-pwsh-persistent product default; the
+      // dsh-terminal-bash value bounds one send plus the complete startup
+      // sequence, so it covers the same cold start (its 30s product default
+      // would not).
+      '    timeoutMs: 300000',
       '    disposeGraceMs: 500',
       "- name: '@deepseek-ai/dsh-tool-pwsh-persistent'",
       '  config:',
-      '    timeoutMs: 60000',
+      '    timeoutMs: 300000',
       '',
     ].join('\n'))