diff --git a/third_party/swiftshader/src/Vulkan/VkPhysicalDevice.cpp b/third_party/swiftshader/src/Vulkan/VkPhysicalDevice.cpp
index acd5909e6c..63b54a880a 100644
--- a/third_party/swiftshader/src/Vulkan/VkPhysicalDevice.cpp
+++ b/third_party/swiftshader/src/Vulkan/VkPhysicalDevice.cpp
@@ -2051,7 +2051,9 @@ void PhysicalDevice::GetFormatProperties(Format format, VkFormatProperties3 *pFo
 	switch(format)
 	{
 	// Formats which can be sampled *and* filtered
-	case VK_FORMAT_R4G4B4A4_UNORM_PACK16:
+	// POC DRIVER SIMULATION: R4G4B4A4 moved to sampled-only group below.
+	// Per Vulkan spec, R4G4B4A4_UNORM_PACK16 has zero mandatory feature bits;
+	// a conforming driver may advertise SAMPLED_IMAGE without FILTER_LINEAR.
 	case VK_FORMAT_B4G4R4A4_UNORM_PACK16:
 	case VK_FORMAT_A4R4G4B4_UNORM_PACK16:
 	case VK_FORMAT_A4B4G4R4_UNORM_PACK16:
@@ -2154,6 +2156,7 @@ void PhysicalDevice::GetFormatProperties(Format format, VkFormatProperties3 *pFo
 		// [[fallthrough]]
 
 	// Formats which can be sampled, but don't support filtering
+	case VK_FORMAT_R4G4B4A4_UNORM_PACK16:  // POC: spec-permitted (no mandatory bits)
 	case VK_FORMAT_R8_UINT:
 	case VK_FORMAT_R8_SINT:
 	case VK_FORMAT_R8G8_UINT: