diff --git a/phpthread.go b/phpthread.go
index a60aa8f0a..010da91ab 100644
--- a/phpthread.go
+++ b/phpthread.go
@@ -79,6 +79,16 @@ func (thread *phpThread) shutdown() {
 	}
 }
 
+// restart the underlying PHP thread
+func (thread *phpThread) restart() {
+	if !thread.state.requestSafeStateChange(stateRestarting) {
+		return
+	}
+	close(thread.drainChan)
+	thread.state.waitFor(stateYielding)
+	thread.drainChan = make(chan struct{})
+}
+
 // change the thread handler safely
 // must be called from outside the PHP thread
 func (thread *phpThread) setHandler(handler threadHandler) {
diff --git a/worker.go b/worker.go
index f28fb3ad6..cffb9840a 100644
--- a/worker.go
+++ b/worker.go
@@ -148,16 +148,8 @@ func drainWorkerThreads() []*phpThread {
 		worker.threadMutex.RLock()
 		ready.Add(len(worker.threads))
 		for _, thread := range worker.threads {
-			if !thread.state.requestSafeStateChange(stateRestarting) {
-				ready.Done()
-				// no state change allowed == thread is shutting down
-				// we'll proceed to restart all other threads anyways
-				continue
-			}
-			close(thread.drainChan)
-			drainedThreads = append(drainedThreads, thread)
 			go func(thread *phpThread) {
-				thread.state.waitFor(stateYielding)
+				thread.restart()
 				ready.Done()
 			}(thread)
 		}