diff --git a/src/vm.ts b/src/vm.ts
index 8d3201c..bb7476c 100644
--- a/src/vm.ts
+++ b/src/vm.ts
@@ -334,12 +334,13 @@ export async function exec(workdir: string, command: string): Promise<{ exitCode
 
 /** Pipe input text to Claude in the container with a prompt, returning the output. */
 export async function claudePipe(input: string, prompt: string): Promise<{ exitCode: number; stdout: string; stderr: string }> {
-  const tmpPath = join(homedir(), '.sandlot', '.claude-pipe-tmp')
+  const tmpName = `.claude-pipe-${crypto.randomUUID()}`
+  const tmpPath = join(homedir(), '.sandlot', tmpName)
   try {
     await Bun.write(tmpPath, input)
     return await exec(
       join(homedir(), '.sandlot'),
-      `cat /sandlot/.claude-pipe-tmp | claude -p "${prompt.replace(/"/g, '\\"')}"`,
+      `cat /sandlot/${tmpName} | claude -p "${prompt.replace(/"/g, '\\"')}"`,
     )
   } finally {
     await Bun.file(tmpPath).unlink().catch(() => {})