diff --git a/OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift b/OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift
index 4411f1a27..bac55cdc2 100644
--- a/OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift	
+++ b/OSBindings/Mac/Clock Signal/Documents/MachineDocument.swift	
@@ -674,8 +674,8 @@ class MachineDocument:
 
 			// Apply labels and create leds entries.
 			for c in 0 ..< leds.count {
-				textFields[c].stringValue = leds[c]
-				self.leds[leds[c]] = LED(levelIndicator: activityIndicators[c])
+				textFields[c].stringValue = leds[c].name
+				self.leds[leds[c].name] = LED(levelIndicator: activityIndicators[c])
 			}
 
 			// Create a fader.
diff --git a/OSBindings/Mac/Clock Signal/Machine/CSMachine.h b/OSBindings/Mac/Clock Signal/Machine/CSMachine.h
index 258073934..745bc9eb3 100644
--- a/OSBindings/Mac/Clock Signal/Machine/CSMachine.h	
+++ b/OSBindings/Mac/Clock Signal/Machine/CSMachine.h	
@@ -33,6 +33,11 @@ typedef NS_ENUM(NSInteger, CSMachineKeyboardInputMode) {
 	CSMachineKeyboardInputModeJoystick,
 };
 
+@interface CSMachineLED: NSObject
+@property(nonatomic, nonnull, readonly) NSString *name;
+@property(nonatomic, readonly) BOOL isPersisent;
+@end
+
 // Deliberately low; to ensure CSMachine has been declared as an @class already.
 #import "CSAtari2600.h"
 #import "CSZX8081.h"
@@ -99,7 +104,7 @@ typedef NS_ENUM(NSInteger, CSMachineKeyboardInputMode) {
 @property (nonatomic, nullable) CSJoystickManager *joystickManager;
 
 // LED list.
-@property (nonatomic, readonly, nonnull) NSArray<NSString *> *leds;
+@property (nonatomic, readonly, nonnull) NSArray<CSMachineLED *> *leds;
 
 // Special-case accessors; undefined behaviour if accessed for a machine not of the corresponding type.
 @property (nonatomic, readonly, nullable) CSAtari2600 *atari2600;
diff --git a/OSBindings/Mac/Clock Signal/Machine/CSMachine.mm b/OSBindings/Mac/Clock Signal/Machine/CSMachine.mm
index 9e7883fa5..843009e58 100644
--- a/OSBindings/Mac/Clock Signal/Machine/CSMachine.mm	
+++ b/OSBindings/Mac/Clock Signal/Machine/CSMachine.mm	
@@ -37,7 +37,7 @@
 @interface CSMachine() <CSScanTargetViewDisplayLinkDelegate>
 - (void)speaker:(Outputs::Speaker::Speaker *)speaker didCompleteSamples:(const int16_t *)samples length:(int)length;
 - (void)speakerDidChangeInputClock:(Outputs::Speaker::Speaker *)speaker;
-- (void)addLED:(NSString *)led;
+- (void)addLED:(NSString *)led isPersistent:(BOOL)isPersistent;
 @end
 
 struct LockProtectedDelegate {
@@ -61,8 +61,8 @@ struct SpeakerDelegate: public Outputs::Speaker::Speaker::Delegate, public LockP
 };
 
 struct ActivityObserver: public Activity::Observer {
-	void register_led(const std::string &name, uint8_t) final {
-		[machine addLED:[NSString stringWithUTF8String:name.c_str()]];
+	void register_led(const std::string &name, uint8_t flags) final {
+		[machine addLED:[NSString stringWithUTF8String:name.c_str()] isPersistent:flags & Activity::Observer::LEDPresentation::Persistent];
 	}
 
 	void set_led_status(const std::string &name, bool lit) final {
@@ -76,6 +76,19 @@ struct ActivityObserver: public Activity::Observer {
 	__unsafe_unretained CSMachine *machine;
 };
 
+@implementation CSMachineLED
+
+- (instancetype)initWithName:(NSString *)name isPersistent:(BOOL)isPersistent {
+	self = [super init];
+	if(self) {
+		_name = name;
+		_isPersisent = isPersistent;
+	}
+	return self;
+}
+
+@end
+
 @implementation CSMachine {
 	SpeakerDelegate _speakerDelegate;
 	ActivityObserver _activityObserver;
@@ -86,7 +99,7 @@ struct ActivityObserver: public Activity::Observer {
 	MachineTypes::JoystickMachine *_joystickMachine;
 
 	CSJoystickManager *_joystickManager;
-	NSMutableArray<NSString *> *_leds;
+	NSMutableArray<CSMachineLED *> *_leds;
 
 	CSHighPrecisionTimer *_timer;
 	std::atomic_flag _isUpdating;
@@ -623,11 +636,11 @@ struct ActivityObserver: public Activity::Observer {
 
 #pragma mark - Activity observation
 
-- (void)addLED:(NSString *)led {
-	[_leds addObject:led];
+- (void)addLED:(NSString *)led isPersistent:(BOOL)isPersistent {
+	[_leds addObject:[[CSMachineLED alloc] initWithName:led isPersistent:isPersistent]];
 }
 
-- (NSArray<NSString *> *)leds {
+- (NSArray<CSMachineLED *> *)leds {
 	return _leds;
 }