diff --git a/src/client.cpp b/src/client.cpp
index bbbdaf7..c112b21 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -111,22 +111,25 @@ int main(int argc, char** argv) {
             fprintf(stderr, "Usage %s start <jobName>\n", argv[0]);
             return EINVAL;
         }
-        kj::Vector<capnp::RemotePromise<LaminarCi::StartResults>> promises;
+        struct: public kj::TaskSet::ErrorHandler {
+            void taskFailed(kj::Exception&&) override {}
+        } ignoreFailed;
+        kj::TaskSet ts(ignoreFailed);
         int jobNameIndex = 2;
         // make a request for each job specified on the commandline
         do {
             auto req = laminar.startRequest();
             req.setJobName(argv[jobNameIndex]);
             int n = setParams(argc - jobNameIndex - 1, &argv[jobNameIndex + 1], req);
-            promises.add(req.send());
+            ts.add(req.send().then([&ret,argv,jobNameIndex](capnp::Response<LaminarCi::StartResults> resp){
+                printf("%s:%d\n", argv[jobNameIndex], resp.getBuildNum());
+                if(resp.getResult() != LaminarCi::JobResult::SUCCESS) {
+                    ret = EFAILED;
+                }
+            }));
             jobNameIndex += n + 1;
         } while(jobNameIndex < argc);
-        // pend on the promises
-        for(auto& p : promises) {
-            if(p.wait(waitScope).getResult() != LaminarCi::JobResult::SUCCESS) {
-                ret = EFAILED;
-            }
-        }
+        ts.onEmpty().wait(waitScope);
     } else if(strcmp(argv[1], "set") == 0) {
         if(argc < 3) {
             fprintf(stderr, "Usage %s set param=value\n", argv[0]);
diff --git a/src/laminar.capnp b/src/laminar.capnp
index 339100c..17ae0c1 100644
--- a/src/laminar.capnp
+++ b/src/laminar.capnp
@@ -3,7 +3,7 @@
 interface LaminarCi {
 
     trigger @0 (jobName :Text, params :List(JobParam)) -> (result :MethodResult);
-    start @1 (jobName :Text, params :List(JobParam)) -> (result :JobResult);
+    start @1 (jobName :Text, params :List(JobParam)) -> (result :JobResult, buildNum :UInt32);
     set @2 (jobName :Text, buildNum :UInt32, param :JobParam) -> (result :MethodResult);
     lock @3 (lockName :Text) -> ();
     release @4 (lockName :Text) -> ();
diff --git a/src/server.cpp b/src/server.cpp
index e20fc75..b4ff9f7 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -114,9 +114,11 @@ public:
         }
         std::shared_ptr<Run> run = laminar.queueJob(jobName, params);
         if(const Run* r = run.get()) {
+            uint num = r->build;
             runWaiters[r].emplace_back(kj::newPromiseAndFulfiller<RunState>());
-            return runWaiters[r].back().promise.then([context](RunState state) mutable {
+            return runWaiters[r].back().promise.then([context,num](RunState state) mutable {
                 context.getResults().setResult(fromRunState(state));
+                context.getResults().setBuildNum(num);
             });
         } else {
             context.getResults().setResult(LaminarCi::JobResult::UNKNOWN);