diff --git a/test/fixtures/test-parallel.behavior.json b/test/fixtures/test-parallel.behavior.json
index 886e49db728..584d20852dc 100644
--- a/test/fixtures/test-parallel.behavior.json
+++ b/test/fixtures/test-parallel.behavior.json
@@ -313,6 +313,14 @@
         "file": "src/channels/plugins/actions/actions.test.ts",
         "reason": "Terminates cleanly under threads, but not process forks on this host."
       },
+      {
+        "file": "src/plugin-sdk/subpaths.test.ts",
+        "reason": "Measured ~23% faster under threads than forks on this host while keeping the file green."
+      },
+      {
+        "file": "src/plugins/install.test.ts",
+        "reason": "Measured ~18% faster under threads than forks on this host while keeping the file green."
+      },
       {
         "file": "src/infra/outbound/deliver.test.ts",
         "reason": "Terminates cleanly under threads, but not process forks on this host."
@@ -333,6 +341,10 @@
         "file": "src/infra/outbound/message-action-runner.context.test.ts",
         "reason": "Terminates cleanly under threads, but not process forks on this host."
       },
+      {
+        "file": "src/infra/provider-usage.test.ts",
+        "reason": "Measured ~17% faster under threads than forks on this host while keeping the file green."
+      },
       {
         "file": "src/tts/tts.test.ts",
         "reason": "Terminates cleanly under threads, but not process forks on this host."