diff --git a/cliamp/cliamp-ws.ts b/cliamp/cliamp-ws.ts
index d3bb564..9c3bd29 100644
--- a/cliamp/cliamp-ws.ts
+++ b/cliamp/cliamp-ws.ts
@@ -107,12 +107,19 @@ function pump(
 function openPlayer(ws: ServerWebSocket<MusicWSData>, files: string): void {
   if (!files) return sendOutput(ws, '\r\n[Error] No files specified.\r\n');
 
-  const cliampPath = findCliamp();
-  if (!cliampPath) return sendOutput(ws, '\r\n[Error] cliamp not found on host.\r\n');
-
+  // Validate the REQUEST before inspecting the HOST, and in that order deliberately.
+  //
+  // It was the other way round until 2026-08-18, which had two costs. A path escaping the owner's home
+  // was answered "cliamp not found on host" on a machine without the binary — telling the caller
+  // something about the host in response to input that should simply have been refused. And the
+  // behaviour this pair is supposed to guarantee became dependent on whether an unrelated binary happens
+  // to be installed, which is what made `cliamp-ws.test.ts` fail on every machine that does not have it.
   const target = resolveInHome(files);
   if (!target) return sendOutput(ws, '\r\n[Error] Invalid file path.\r\n');
 
+  const cliampPath = findCliamp();
+  if (!cliampPath) return sendOutput(ws, '\r\n[Error] cliamp not found on host.\r\n');
+
   // `script` fakes a PTY for cliamp, which avoids a node-pty native dependency here.
   const cliampCmd = `${shellEscape(cliampPath)} ${shellEscape(target)}`;
   console.log(`[music] cliamp spawning: ${cliampCmd}`);