diff --git a/src/signal-manager.h b/src/signal-manager.h
index a063fc4..ea1b796 100644
--- a/src/signal-manager.h
+++ b/src/signal-manager.h
@@ -73,7 +73,7 @@ class SignalManager{
 			while(loop){
 				std::chrono::duration<double, std::micro> diff = std::chrono::steady_clock::now() - last;
 				if(diff.count() > 500){
-					//mutex->lock();
+					mutex->lock();
 					if(play){
 						for(auto& s : signals){
 							s.direction = (s.next->position - s.position).norm();
@@ -91,9 +91,9 @@ class SignalManager{
 							}
 						}
 					}
-					//mutex->unlock();
+					midi.update();
+					mutex->unlock();
 				last = std::chrono::steady_clock::now();
-				midi.update();
 				}
 			}
 		}