diff --git a/src/Vulkan/VkInstance.cpp b/src/Vulkan/VkInstance.cpp
index e4079b8..f93dc7f 100644
--- a/src/Vulkan/VkInstance.cpp
+++ b/src/Vulkan/VkInstance.cpp
@@ -19,8 +19,7 @@
 {
 
 Instance::Instance(const VkInstanceCreateInfo* pCreateInfo, void* mem, VkPhysicalDevice physicalDevice)
-	: physicalDevice(physicalDevice),
-	  physicalDeviceCount(physicalDevice ? 1 : 0)
+	: physicalDevice(physicalDevice)
 {
 }
 
@@ -29,31 +28,45 @@
 	vk::destroy(physicalDevice, pAllocator);
 }
 
-uint32_t Instance::getPhysicalDeviceCount() const
+VkResult Instance::getPhysicalDevices(uint32_t *pPhysicalDeviceCount, VkPhysicalDevice* pPhysicalDevices) const
 {
-	return physicalDeviceCount;
+	if (!pPhysicalDevices)
+	{
+		*pPhysicalDeviceCount = 1;
+		return VK_SUCCESS;
+	}
+
+	if (*pPhysicalDeviceCount < 1)
+	{
+		return VK_INCOMPLETE;
+	}
+
+	pPhysicalDevices[0] = physicalDevice;
+	*pPhysicalDeviceCount = 1;
+
+	return VK_SUCCESS;
 }
 
-void Instance::getPhysicalDevices(uint32_t pPhysicalDeviceCount, VkPhysicalDevice* pPhysicalDevices) const
+VkResult Instance::getPhysicalDeviceGroups(uint32_t *pPhysicalDeviceGroupCount,
+                                           VkPhysicalDeviceGroupProperties* pPhysicalDeviceGroupProperties) const
 {
-	ASSERT(pPhysicalDeviceCount == 1);
+	if (!pPhysicalDeviceGroupProperties)
+	{
+		*pPhysicalDeviceGroupCount = 1;
+		return VK_SUCCESS;
+	}
 
-	*pPhysicalDevices = physicalDevice;
-}
+	if (*pPhysicalDeviceGroupCount < 1)
+	{
+		return VK_INCOMPLETE;
+	}
 
-uint32_t Instance::getPhysicalDeviceGroupCount() const
-{
-	return physicalDeviceGroupCount;
-}
+	pPhysicalDeviceGroupProperties[0].physicalDeviceCount = 1;
+	pPhysicalDeviceGroupProperties[0].physicalDevices[0] = physicalDevice;
+	pPhysicalDeviceGroupProperties[0].subsetAllocation = VK_FALSE;
+	*pPhysicalDeviceGroupCount = 1;
 
-void Instance::getPhysicalDeviceGroups(uint32_t pPhysicalDeviceGroupCount,
-                                       VkPhysicalDeviceGroupProperties* pPhysicalDeviceGroupProperties) const
-{
-	ASSERT(pPhysicalDeviceGroupCount == 1);
-
-	pPhysicalDeviceGroupProperties->physicalDeviceCount = physicalDeviceCount;
-	pPhysicalDeviceGroupProperties->physicalDevices[0] = physicalDevice;
-	pPhysicalDeviceGroupProperties->subsetAllocation = VK_FALSE;
+	return VK_SUCCESS;
 }
 
 } // namespace vk
diff --git a/src/Vulkan/VkInstance.hpp b/src/Vulkan/VkInstance.hpp
index f63dc3b..10eac6d 100644
--- a/src/Vulkan/VkInstance.hpp
+++ b/src/Vulkan/VkInstance.hpp
@@ -30,16 +30,12 @@
 
 	static size_t ComputeRequiredAllocationSize(const VkInstanceCreateInfo*) { return 0; }
 
-	uint32_t getPhysicalDeviceCount() const;
-	void getPhysicalDevices(uint32_t pPhysicalDeviceCount, VkPhysicalDevice* pPhysicalDevices) const;
-	uint32_t getPhysicalDeviceGroupCount() const;
-	void getPhysicalDeviceGroups(uint32_t pPhysicalDeviceGroupCount,
+	VkResult getPhysicalDevices(uint32_t *pPhysicalDeviceCount, VkPhysicalDevice* pPhysicalDevices) const;
+	VkResult getPhysicalDeviceGroups(uint32_t *pPhysicalDeviceGroupCount,
                                  VkPhysicalDeviceGroupProperties* pPhysicalDeviceGroupProperties) const;
 
 private:
 	VkPhysicalDevice physicalDevice = VK_NULL_HANDLE;
-	const uint32_t physicalDeviceCount = 0;
-	const uint32_t physicalDeviceGroupCount = 1;
 };
 
 using DispatchableInstance = DispatchableObject<Instance, VkInstance>;
diff --git a/src/Vulkan/libVulkan.cpp b/src/Vulkan/libVulkan.cpp
index 3a68c40..bc39d38 100644
--- a/src/Vulkan/libVulkan.cpp
+++ b/src/Vulkan/libVulkan.cpp
@@ -200,16 +200,7 @@
 	TRACE("(VkInstance instance = %p, uint32_t* pPhysicalDeviceCount = %p, VkPhysicalDevice* pPhysicalDevices = %p)",
 		    instance, pPhysicalDeviceCount, pPhysicalDevices);
 
-	if(!pPhysicalDevices)
-	{
-		*pPhysicalDeviceCount = vk::Cast(instance)->getPhysicalDeviceCount();
-	}
-	else
-	{
-		vk::Cast(instance)->getPhysicalDevices(*pPhysicalDeviceCount, pPhysicalDevices);
-	}
-
-	return VK_SUCCESS;
+	return vk::Cast(instance)->getPhysicalDevices(pPhysicalDeviceCount, pPhysicalDevices);
 }
 
 VKAPI_ATTR void VKAPI_CALL vkGetPhysicalDeviceFeatures(VkPhysicalDevice physicalDevice, VkPhysicalDeviceFeatures* pFeatures)
@@ -527,12 +518,14 @@
 		return VK_SUCCESS;
 	}
 
-	for(uint32_t i = 0; i < std::min(*pPropertyCount, extensionPropertiesCount); i++)
+	auto toCopy = std::min(*pPropertyCount, extensionPropertiesCount);
+	for(uint32_t i = 0; i < toCopy; i++)
 	{
 		pProperties[i] = instanceExtensionProperties[i];
 	}
 
-	return (*pPropertyCount < extensionPropertiesCount) ? VK_INCOMPLETE : VK_SUCCESS;
+	*pPropertyCount = toCopy;
+	return (toCopy < extensionPropertiesCount) ? VK_INCOMPLETE : VK_SUCCESS;
 }
 
 VKAPI_ATTR VkResult VKAPI_CALL vkEnumerateDeviceExtensionProperties(VkPhysicalDevice physicalDevice, const char* pLayerName, uint32_t* pPropertyCount, VkExtensionProperties* pProperties)
@@ -547,12 +540,14 @@
 		return VK_SUCCESS;
 	}
 
-	for(uint32_t i = 0; i < std::min(*pPropertyCount, extensionPropertiesCount); i++)
+	auto toCopy = std::min(*pPropertyCount, extensionPropertiesCount);
+	for(uint32_t i = 0; i < toCopy; i++)
 	{
 		pProperties[i] = deviceExtensionProperties[i];
 	}
 
-	return (*pPropertyCount < extensionPropertiesCount) ? VK_INCOMPLETE : VK_SUCCESS;
+	*pPropertyCount = toCopy;
+	return (toCopy < extensionPropertiesCount) ? VK_INCOMPLETE : VK_SUCCESS;
 }
 
 VKAPI_ATTR VkResult VKAPI_CALL vkEnumerateInstanceLayerProperties(uint32_t* pPropertyCount, VkLayerProperties* pProperties)
@@ -2082,16 +2077,7 @@
 	TRACE("VkInstance instance = %p, uint32_t* pPhysicalDeviceGroupCount = %p, VkPhysicalDeviceGroupProperties* pPhysicalDeviceGroupProperties = %p",
 	      instance, pPhysicalDeviceGroupCount, pPhysicalDeviceGroupProperties);
 
-	if(!pPhysicalDeviceGroupProperties)
-	{
-		*pPhysicalDeviceGroupCount = vk::Cast(instance)->getPhysicalDeviceGroupCount();
-	}
-	else
-	{
-		vk::Cast(instance)->getPhysicalDeviceGroups(*pPhysicalDeviceGroupCount, pPhysicalDeviceGroupProperties);
-	}
-
-	return VK_SUCCESS;
+	return vk::Cast(instance)->getPhysicalDeviceGroups(pPhysicalDeviceGroupCount, pPhysicalDeviceGroupProperties);
 }
 
 VKAPI_ATTR void VKAPI_CALL vkGetImageMemoryRequirements2(VkDevice device, const VkImageMemoryRequirementsInfo2* pInfo, VkMemoryRequirements2* pMemoryRequirements)