diff --git a/packages/kbn-dev-utils/src/proc_runner/proc.js b/packages/kbn-dev-utils/src/proc_runner/proc.js
index 847933014349..198858a27c3f 100644
--- a/packages/kbn-dev-utils/src/proc_runner/proc.js
+++ b/packages/kbn-dev-utils/src/proc_runner/proc.js
@@ -122,10 +122,13 @@ export function createProc(name, { cmd, args, cwd, env, stdin, log }) {
       await withTimeout(
         async () => {
           await treeKillAsync(childProcess.pid, signal);
+          await this.getOutcomePromise();
         },
         STOP_TIMEOUT,
         async () => {
-          log.warning(`Proc "${name}" was sent "${signal}" and didn't exit after ${STOP_TIMEOUT} ms, sending SIGKILL`);
+          log.warning(
+            `Proc "${name}" was sent "${signal}" and didn't emit the "exit" or "error" events after ${STOP_TIMEOUT} ms, sending SIGKILL`
+          );
           await treeKillAsync(childProcess.pid, 'SIGKILL');
         }
       );