diff --git a/process/process.go b/process/process.go
index 4bfcb4b4..d1754822 100644
--- a/process/process.go
+++ b/process/process.go
@@ -593,6 +593,10 @@ func (p *process) stop(wait bool) error {
 		if p.callbacks.onExit == nil {
 			p.callbacks.onExit = func() {
 				wg.Done()
+
+				p.callbacks.lock.Lock()
+				defer p.callbacks.lock.Unlock()
+
 				p.callbacks.onExit = nil
 			}
 		} else {
@@ -600,6 +604,10 @@ func (p *process) stop(wait bool) error {
 			p.callbacks.onExit = func() {
 				cb()
 				wg.Done()
+
+				p.callbacks.lock.Lock()
+				defer p.callbacks.lock.Unlock()
+
 				p.callbacks.onExit = cb
 			}
 		}