diff --git a/packages/harness/tests/claude-session.test.mjs b/packages/harness/tests/claude-session.test.mjs
index bf5cb2d29..d9c45e446 100644
--- a/packages/harness/tests/claude-session.test.mjs
+++ b/packages/harness/tests/claude-session.test.mjs
@@ -269,7 +269,7 @@ test("claude adapter: a directory pin exits 2 before it runs; a pin with a space
 
 test("claude: CLAUDE.md files and auto-memory don't reach the model; without --restricted they do", { skip }, async (t) => {
   const { dir, workspace, env } = await session(t, []);
-  const slug = realpathSync(workspace).replace(/[/.]/g, "-");
+  const slug = realpathSync(workspace).replace(/[^A-Za-z0-9]/g, "-");
   const plant = {
     "MARKER-USER": [join(env.HOME, ".claude", "CLAUDE.md"), join(env.CLAUDE_CONFIG_DIR, "CLAUDE.md")],
     "MARKER-PARENT": [join(dir, "CLAUDE.md")],