diff --git a/packages/bus/src/broker.mjs b/packages/bus/src/broker.mjs
index d5e6f2bc3..b18965feb 100644
--- a/packages/bus/src/broker.mjs
+++ b/packages/bus/src/broker.mjs
@@ -1848,6 +1848,11 @@ export class Broker {
         if (a.class === 'BLOCK') this.#checkBlock(s, to, a.in_reply_to);
         if (a.decision) this.#decision(s, a.decision);
         const thread = this.#threadFor(s, to, a.in_reply_to);
+        // Row 170 (#1667): a tester's message to a role nobody holds is refused before it is
+        // stored, so a PM test never waits for the role's next run. A run launched but not yet
+        // claimed counts as no holder, as in #waiting. No lock: a holder that releases once the
+        // message is routed leaves it like any other message it held.
+        if (s.tester && !this.#recipient(s.business, to, thread)) fail('tester-target-not-running');
         const mid = randomUUID();
         this.#store.run(
           'INSERT INTO messages(id,at,business,from_role,from_run,to_role,to_name,class,in_reply_to,decision,corrects,body) VALUES(?,?,?,?,?,?,?,?,?,?,?,?)',
@@ -2489,7 +2494,8 @@ export class Broker {
   // told and whether launch.by itself has a holder. A run launched but not yet claimed counts as
   // no holder; the instance-running refusal stops a second launch. launch.by isn't told of a
   // message to it, of its own message (this result tells it) or of a tester's (a PM test
-  // authorizes nothing). Row 152 (#1646): launchable says whether the target is one of
+  // authorizes nothing); since row 170 (#1667) message.send refuses a tester's message to a role
+  // nobody holds before it gets here. Row 152 (#1646): launchable says whether the target is one of
   // launch.instances, so the sender learns at once that no launch can follow. launch.by is
   // still told: the Console shows the notice as the reply to the human's message.
   #waiting(s, mid, to, thread) {
diff --git a/packages/cli/README.md b/packages/cli/README.md
index fb3ad8350..3ed8916d0 100644
--- a/packages/cli/README.md
+++ b/packages/cli/README.md
@@ -127,8 +127,8 @@ mosaic launches list [--json]
   when the bus told `launch.by`; `pm isn't running, and the business names
   no launch.by` with no launch block; `pm isn't running and isn't in the
   launch block, so chief can't launch it` when the role isn't one of
-  `launch.instances` (row 152, #1646); `pm isn't running; a tester's message
-  tells nobody to launch it` for `--tester`. When `launch.by` itself isn't
+  `launch.instances` (row 152, #1646). A `--tester` message to such a role is
+  refused instead (see `--tester` below). When `launch.by` itself isn't
   running, talk prints `<launch.by> isn't running` (or `isn't running
   either` after the told line, but not after the launch-block line) and the
   command that starts it:
@@ -168,8 +168,12 @@ mosaic launches list [--json]
   (`tester-off`), each exit 3. Like the human commands, `--tester` works
   only from the tree the bus runs from ("One pinned copy" below).
   `talk --tester` text must start with
-  `[mos test]`, else exit 2 before any call. The role's reply comes back to
-  the tester, not to the human's inbox. `decide`, `stop`, `launches` and
+  `[mos test]`, else exit 2 before any call. When no run holds the role
+  (row 170, #1667), the bus refuses the message with
+  `tester-target-not-running` and stores nothing, and talk prints `pm isn't
+  running, so the tester's message was refused and nothing was stored` and
+  exits 3. A run launched but not yet claimed counts as not running. The
+  role's reply comes back to the tester, not to the human's inbox. `decide`, `stop`, `launches` and
   `inbox --read` or `--read-all` take no `--tester` (exit 4).
 
 ## The app
diff --git a/packages/cli/src/cli.mjs b/packages/cli/src/cli.mjs
index 6a4f68be6..35a70a5d3 100644
--- a/packages/cli/src/cli.mjs
+++ b/packages/cli/src/cli.mjs
@@ -339,8 +339,6 @@ function waitingLines(w, business) {
   // Row 152 (#1646): launch.by can launch only launch.instances. An older bus sends no
   // launchable, so only an explicit false prints this line.
   if (w.launchable === false) return `${w.role} isn't running and isn't in the launch block, so ${w.launcher} can't launch it\n`;
-  // A human's message to another role always tells launch.by; a tester's never does.
-  if (!w.told) return `${w.role} isn't running; a tester's message tells nobody to launch it\n`;
   return `${w.role} isn't running, ${w.launcher} has been told\n` + (w.launcherRunning ? "" : restart(w.launcher, " either"));
 }
 
@@ -383,6 +381,11 @@ async function talk(rest, io, deps, receiveOnly = false) {
       if (e.code === "thread-required-use-thread-send") {
         throw new CliError(`${to} runs in threads, so a message to it names one: mosaic talk --thread <thread> <text>; mosaic threads lists yours`, 2);
       }
+      // Row 170 (#1667): the bus stores no tester message to a role nobody holds. Exit 3 like the
+      // other tester refusals; transport.mjs's EXIT map stays as row 164 pinned it.
+      if (e.code === "tester-target-not-running" && parsed.flags.has("--tester")) {
+        throw new CliError(`${to} isn't running, so the tester's message was refused and nothing was stored`, 3);
+      }
       throw e;
     }
     io.stdout.write(`sent ${shortId(sent.id)} to ${to}\n`);