diff --git a/Docs/Whats_New.md b/Docs/Whats_New.md
index a2efc7d..b54e5ab 100644
--- a/Docs/Whats_New.md
+++ b/Docs/Whats_New.md
@@ -13,6 +13,16 @@
 
 
 
+MoltenVK 1.1.12
+--------------
+
+Released TBD
+
+- Fix occassional crash from retention of `MVKSwapchain` for future drawable presentations.
+- Add `MVK_USE_CEREAL` build setting to avoid use of Cereal external library (for pipeline caching).
+
+
+
 MoltenVK 1.1.11
 --------------
 
diff --git a/MoltenVK/MoltenVK/API/vk_mvk_moltenvk.h b/MoltenVK/MoltenVK/API/vk_mvk_moltenvk.h
index 70d6030..080bb02 100644
--- a/MoltenVK/MoltenVK/API/vk_mvk_moltenvk.h
+++ b/MoltenVK/MoltenVK/API/vk_mvk_moltenvk.h
@@ -51,7 +51,7 @@
  */
 #define MVK_VERSION_MAJOR   1
 #define MVK_VERSION_MINOR   1
-#define MVK_VERSION_PATCH   11
+#define MVK_VERSION_PATCH   12
 
 #define MVK_MAKE_VERSION(major, minor, patch)    (((major) * 10000) + ((minor) * 100) + (patch))
 #define MVK_VERSION     MVK_MAKE_VERSION(MVK_VERSION_MAJOR, MVK_VERSION_MINOR, MVK_VERSION_PATCH)
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKImage.h b/MoltenVK/MoltenVK/GPUObjects/MVKImage.h
index b56eeb0..fc9e5fd 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKImage.h
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKImage.h
@@ -393,20 +393,21 @@
 
 #pragma mark Construction
 
-	/** Constructs an instance for the specified device and swapchain. */
 	MVKSwapchainImage(MVKDevice* device,
 					  const VkImageCreateInfo* pCreateInfo,
 					  MVKSwapchain* swapchain,
 					  uint32_t swapchainIndex);
 
-	~MVKSwapchainImage() override;
+	void destroy() override;
 
 protected:
 	friend class MVKPeerSwapchainImage;
 
 	virtual id<CAMetalDrawable> getCAMetalDrawable() = 0;
+	void detachSwapchain();
 
 	MVKSwapchain* _swapchain;
+	std::mutex _swapchainLock;
 	uint32_t _swapchainIndex;
 };
 
@@ -452,7 +453,6 @@
 
 #pragma mark Construction
 
-	/** Constructs an instance for the specified device and swapchain. */
 	MVKPresentableSwapchainImage(MVKDevice* device,
 								 const VkImageCreateInfo* pCreateInfo,
 								 MVKSwapchain* swapchain,
@@ -464,7 +464,7 @@
 	friend MVKSwapchain;
 
 	id<CAMetalDrawable> getCAMetalDrawable() override;
-	void presentCAMetalDrawable(id<CAMetalDrawable> mtlDrawable, MVKPresentTimingInfo presentTimingInfo);
+	void addPresentedHandler(id<CAMetalDrawable> mtlDrawable, MVKPresentTimingInfo presentTimingInfo);
 	void releaseMetalDrawable();
 	MVKSwapchainImageAvailability getAvailability();
 	void makeAvailable(const MVKSwapchainSignaler& signaler);
@@ -498,7 +498,6 @@
 
 #pragma mark Construction
 
-	/** Constructs an instance for the specified device and swapchain. */
 	MVKPeerSwapchainImage(MVKDevice* device,
 						  const VkImageCreateInfo* pCreateInfo,
 						  MVKSwapchain* swapchain,
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKImage.mm b/MoltenVK/MoltenVK/GPUObjects/MVKImage.mm
index 8340095..dc85fd4 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKImage.mm
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKImage.mm
@@ -1190,12 +1190,16 @@
 									 uint32_t swapchainIndex) : MVKImage(device, pCreateInfo) {
 	_swapchain = swapchain;
 	_swapchainIndex = swapchainIndex;
-
-	_swapchain->retain();
 }
 
-MVKSwapchainImage::~MVKSwapchainImage() {
-	if (_swapchain) { _swapchain->release(); }
+void MVKSwapchainImage::detachSwapchain() {
+	lock_guard<mutex> lock(_swapchainLock);
+	_swapchain = nullptr;
+}
+
+void MVKSwapchainImage::destroy() {
+	detachSwapchain();
+	MVKImage::destroy();
 }
 
 
@@ -1308,10 +1312,19 @@
 
 	_swapchain->willPresentSurface(getMTLTexture(0), mtlCmdBuff);
 
-	// Get current drawable now. Don't retrieve in handler, because a new drawable might be acquired by then.
+	// According to Apple, it is more performant to call MTLDrawable present from within a
+	// MTLCommandBuffer scheduled-handler than it is to call MTLCommandBuffer presentDrawable:.
+	// But get current drawable now, intead of in handler, because a new drawable might be acquired by then.
+	// Attach present handler before presenting to avoid race condition.
 	id<CAMetalDrawable> mtlDrwbl = getCAMetalDrawable();
 	[mtlCmdBuff addScheduledHandler: ^(id<MTLCommandBuffer> mcb) {
-		presentCAMetalDrawable(mtlDrwbl, presentTimingInfo);
+		if (presentTimingInfo.hasPresentTime) {
+			// Convert from nsecs to seconds for Metal
+			addPresentedHandler(mtlDrwbl, presentTimingInfo);
+			[mtlDrwbl presentAtTime: (double)presentTimingInfo.desiredPresentTime * 1.0e-9];
+		} else {
+			[mtlDrwbl present];
+		}
 	}];
 
 	MVKSwapchainSignaler signaler;
@@ -1342,33 +1355,29 @@
 	signalPresentationSemaphore(signaler, mtlCmdBuff);
 }
 
-void MVKPresentableSwapchainImage::presentCAMetalDrawable(id<CAMetalDrawable> mtlDrawable,
-														  MVKPresentTimingInfo presentTimingInfo) {
-
-	if (presentTimingInfo.hasPresentTime) {
-
-		// Attach present handler before presenting to avoid race condition.
-		// If MTLDrawable.presentedTime/addPresentedHandler isn't supported,
-		// treat it as if the present happened when requested.
-#if MVK_OS_SIMULATOR
-		_swapchain->recordPresentTime(presentTimingInfo);
-#else
-		if ([mtlDrawable respondsToSelector: @selector(addPresentedHandler:)]) {
-			// Ensure this image is not destroyed while awaiting presentation
-			retain();
-			[mtlDrawable addPresentedHandler: ^(id<MTLDrawable> drawable) {
-				_swapchain->recordPresentTime(presentTimingInfo, drawable.presentedTime * 1.0e9);
-				release();
-			}];
-		} else {
-			_swapchain->recordPresentTime(presentTimingInfo);
-		}
-#endif
-		// Convert from nsecs to seconds for Metal
-		[mtlDrawable presentAtTime: (double)presentTimingInfo.desiredPresentTime * 1.0e-9];
-	} else {
-		[mtlDrawable present];
+void MVKPresentableSwapchainImage::addPresentedHandler(id<CAMetalDrawable> mtlDrawable,
+													   MVKPresentTimingInfo presentTimingInfo) {
+#if !MVK_OS_SIMULATOR
+	if ([mtlDrawable respondsToSelector: @selector(addPresentedHandler:)]) {
+		retain();	// Ensure this image is not destroyed while awaiting presentation
+		[mtlDrawable addPresentedHandler: ^(id<MTLDrawable> drawable) {
+			// Since we're in a callback, it's possible that the swapchain has been released by now.
+			// Lock the swapchain, and test if it is present before doing anything with it.
+			lock_guard<mutex> cblock(_swapchainLock);
+			if (_swapchain) { _swapchain->recordPresentTime(presentTimingInfo, drawable.presentedTime * 1.0e9); }
+			release();
+		}];
+		return;
 	}
+#endif
+
+	// If MTLDrawable.presentedTime/addPresentedHandler isn't supported,
+	// treat it as if the present happened when requested.
+	// Since this function may be called in a callback, it's possible that
+	// the swapchain has been released by the time this function runs.
+	// Lock the swapchain, and test if it is present before doing anything with it.
+	lock_guard<mutex> lock(_swapchainLock);
+	if (_swapchain) {_swapchain->recordPresentTime(presentTimingInfo); }
 }
 
 // Resets the MTLTexture and CAMetalDrawable underlying this image.
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKSurface.h b/MoltenVK/MoltenVK/GPUObjects/MVKSurface.h
index bcb69fd..8ec3eb1 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKSurface.h
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKSurface.h
@@ -58,7 +58,7 @@
 
     /** Returns the CAMetalLayer underlying this surface.  */
     inline CAMetalLayer* getCAMetalLayer() {
-        std::lock_guard<std::mutex> lock(_lock);
+        std::lock_guard<std::mutex> lock(_layerLock);
         return _mtlCAMetalLayer;
     }
 
@@ -78,10 +78,11 @@
 protected:
 	void propagateDebugName() override {}
 	void initLayerObserver();
+	void releaseLayer();
 
 	MVKInstance* _mvkInstance;
 	CAMetalLayer* _mtlCAMetalLayer;
-	std::mutex _lock;
 	MVKBlockObserver* _layerObserver;
+	std::mutex _layerLock;
 };
 
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKSurface.mm b/MoltenVK/MoltenVK/GPUObjects/MVKSurface.mm
index a70537c..a355177 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKSurface.mm
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKSurface.mm
@@ -77,18 +77,20 @@
 
 	_layerObserver = [MVKBlockObserver observerWithBlock: ^(NSString* path, id, NSDictionary*, void*) {
 		if ( ![path isEqualToString: @"layer"] ) { return; }
-		std::lock_guard<std::mutex> lock(this->_lock);
-		[this->_mtlCAMetalLayer release];
-		this->_mtlCAMetalLayer = nil;
-		this->setConfigurationResult(VK_ERROR_SURFACE_LOST_KHR);
-		[this->_layerObserver release];
-		this->_layerObserver = nil;
+		this->releaseLayer();
 	} forObject: _mtlCAMetalLayer.delegate atKeyPath: @"layer"];
 }
 
-MVKSurface::~MVKSurface() {
-	std::lock_guard<std::mutex> lock(_lock);
+void MVKSurface::releaseLayer() {
+	std::lock_guard<std::mutex> lock(_layerLock);
+	setConfigurationResult(VK_ERROR_SURFACE_LOST_KHR);
 	[_mtlCAMetalLayer release];
+	_mtlCAMetalLayer = nil;
 	[_layerObserver release];
+	_layerObserver = nil;
+}
+
+MVKSurface::~MVKSurface() {
+	releaseLayer();
 }
 
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.h b/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.h
index 7521e65..76ae1ce 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.h
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.h
@@ -21,6 +21,7 @@
 #include "MVKDevice.h"
 #include "MVKImage.h"
 #include "MVKSmallVector.h"
+#include <mutex>
 
 #import "CAMetalLayer+MoltenVK.h"
 #import <Metal/Metal.h>
@@ -111,6 +112,7 @@
 	void propagateDebugName() override;
 	void initCAMetalLayer(const VkSwapchainCreateInfoKHR* pCreateInfo, uint32_t imgCnt);
 	void initSurfaceImages(const VkSwapchainCreateInfoKHR* pCreateInfo, uint32_t imgCnt);
+	void releaseLayer();
 	void releaseUndisplayedSurfaces();
 	uint64_t getNextAcquisitionID();
     void willPresentSurface(id<MTLTexture> mtlTexture, id<MTLCommandBuffer> mtlCmdBuff);
@@ -126,6 +128,7 @@
     uint32_t _currentPerfLogFrameCount;
     std::atomic<bool> _surfaceLost;
     MVKBlockObserver* _layerObserver;
+	std::mutex _layerLock;
 	static const int kMaxPresentationHistory = 60;
 	VkPastPresentationTimingGOOGLE _presentTimingHistory[kMaxPresentationHistory];
 	uint32_t _presentHistoryCount;
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.mm b/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.mm
index d614790..781f72b 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.mm
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.mm
@@ -255,13 +255,13 @@
 void MVKSwapchain::initCAMetalLayer(const VkSwapchainCreateInfoKHR* pCreateInfo, uint32_t imgCnt) {
 
 	MVKSurface* mvkSrfc = (MVKSurface*)pCreateInfo->surface;
-	if ( !mvkSrfc->getCAMetalLayer() ) {
+	_mtlLayer = mvkSrfc->getCAMetalLayer();
+	if ( !_mtlLayer ) {
 		setConfigurationResult(mvkSrfc->getConfigurationResult());
 		_surfaceLost = true;
 		return;
 	}
 
-	_mtlLayer = mvkSrfc->getCAMetalLayer();
 	_mtlLayer.device = getMTLDevice();
 	_mtlLayer.pixelFormat = getPixelFormats()->getMTLPixelFormat(pCreateInfo->imageFormat);
 	_mtlLayer.maximumDrawableCountMVK = imgCnt;
@@ -341,13 +341,18 @@
 		// needs to recreate the swapchain, or no content will be displayed.
 		_layerObserver = [MVKBlockObserver observerWithBlock: ^(NSString* path, id, NSDictionary*, void*) {
 			if ( ![path isEqualToString: @"layer"] ) { return; }
-			this->_surfaceLost = true;
-			[this->_layerObserver release];
-			this->_layerObserver = nil;
+			this->releaseLayer();
 		} forObject: _mtlLayer.delegate atKeyPath: @"layer"];
 	}
 }
 
+void MVKSwapchain::releaseLayer() {
+	std::lock_guard<std::mutex> lock(_layerLock);
+	_surfaceLost = true;
+	[_layerObserver release];
+	_layerObserver = nil;
+}
+
 // Initializes the array of images used for the surface of this swapchain.
 // The CAMetalLayer should already be initialized when this is called.
 void MVKSwapchain::initSurfaceImages(const VkSwapchainCreateInfoKHR* pCreateInfo, uint32_t imgCnt) {
@@ -494,6 +499,6 @@
 
 MVKSwapchain::~MVKSwapchain() {
     if (_licenseWatermark) { _licenseWatermark->destroy(); }
-    [this->_layerObserver release];
+	releaseLayer();
 }