diff --git a/OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift b/OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift
index a29f1fad4..028372e2e 100644
--- a/OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift	
+++ b/OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift	
@@ -92,6 +92,7 @@ class MachineDocument:
 	}
 
 	override func close() {
+		bestEffortUpdater.flush()
 		actionLock.lock()
 		drawLock.lock()
 		openGLView.invalidate()
diff --git a/OSBindings/Mac/Clock Signal/Updater/CSBestEffortUpdater.h b/OSBindings/Mac/Clock Signal/Updater/CSBestEffortUpdater.h
index 2ed7a43bc..7130f3636 100644
--- a/OSBindings/Mac/Clock Signal/Updater/CSBestEffortUpdater.h	
+++ b/OSBindings/Mac/Clock Signal/Updater/CSBestEffortUpdater.h	
@@ -25,5 +25,6 @@
 @property (nonatomic, weak) id<CSBestEffortUpdaterDelegate> delegate;
 
 - (void)update;
+- (void)flush;
 
 @end
diff --git a/OSBindings/Mac/Clock Signal/Updater/CSBestEffortUpdater.m b/OSBindings/Mac/Clock Signal/Updater/CSBestEffortUpdater.m
index 10c0a133d..309324f42 100644
--- a/OSBindings/Mac/Clock Signal/Updater/CSBestEffortUpdater.m	
+++ b/OSBindings/Mac/Clock Signal/Updater/CSBestEffortUpdater.m	
@@ -63,4 +63,9 @@
 	}
 }
 
+- (void)flush
+{
+	dispatch_sync(_serialDispatchQueue, ^{});
+}
+
 @end