diff --git a/HandyJSON.xcodeproj/project.pbxproj b/HandyJSON.xcodeproj/project.pbxproj
index 7913ee0..507a225 100644
--- a/HandyJSON.xcodeproj/project.pbxproj
+++ b/HandyJSON.xcodeproj/project.pbxproj
@@ -1323,7 +1323,7 @@
 				ENABLE_BITCODE = NO;
 				INFOPLIST_FILE = "$(SRCROOT)/Source/Info-iOS.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.aliyun.app.HandyJSON;
 				PRODUCT_NAME = "$(PROJECT_NAME)";
@@ -1347,7 +1347,7 @@
 				ENABLE_BITCODE = NO;
 				INFOPLIST_FILE = "$(SRCROOT)/Source/Info-iOS.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.aliyun.app.HandyJSON;
 				PRODUCT_NAME = "$(PROJECT_NAME)";
@@ -1366,7 +1366,7 @@
 				DEVELOPMENT_TEAM = QBMN2BBW3K;
 				ENABLE_BITCODE = NO;
 				INFOPLIST_FILE = HandyJSONDemo/Info.plist;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.aliyun.app.HandyJSONDemo;
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -1386,7 +1386,7 @@
 				DEVELOPMENT_TEAM = QBMN2BBW3K;
 				ENABLE_BITCODE = NO;
 				INFOPLIST_FILE = HandyJSONDemo/Info.plist;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.aliyun.app.HandyJSONDemo;
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -1402,7 +1402,7 @@
 				BUNDLE_LOADER = "$(TEST_HOST)";
 				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = "Tests/HandyJSONTests/Info-iOS.plist";
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.aliyun.app.HandyJSONTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
@@ -1417,7 +1417,7 @@
 				BUNDLE_LOADER = "$(TEST_HOST)";
 				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = "Tests/HandyJSONTests/Info-iOS.plist";
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.aliyun.app.HandyJSONTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
diff --git a/Source/Metadata.swift b/Source/Metadata.swift
index 35d78b3..55d1a61 100755
--- a/Source/Metadata.swift
+++ b/Source/Metadata.swift
@@ -186,7 +186,20 @@ extension Metadata {
         }
 
         func _propertyDescriptionsAndStartPoint() -> ([Property.Description], Int32?)? {
-            let instanceStart = pointer.pointee.class_rw_t()?.pointee.class_ro_t()?.pointee.instanceStart
+            // swift/include/swift/Remote/MetadataReader.h
+            guard let flags = pointer.pointee.flags() else {
+                return nil
+            }
+            let RO_REALIZED: UInt32 = 0x80000000
+            let isRealized = (flags & RO_REALIZED) != 0
+            var ro:  UnsafePointer<_class_ro_t>?
+            if isRealized {
+                ro = pointer.pointee.class_rw_t()?.pointee.class_ro_t()
+            } else {
+                ro = pointer.pointee.class_ro_t()
+            }
+            
+            let instanceStart = ro?.pointee.instanceStart
             var result: [Property.Description] = []
             if let fieldOffsets = self.fieldOffsets, let fieldRecords = self.reflectionFieldDescriptor?.fieldRecords {
                 class NameAndType {
@@ -256,6 +269,27 @@ extension _Metadata {
                 return UnsafePointer<_class_rw_t>(bitPattern: self.rodataPointer & 0xfffffffc)
             }
         }
+        
+        /// Read the flags, which is a 32-bit header on both formats.
+        func flags() -> UInt32? {
+            if MemoryLayout<Int>.size == MemoryLayout<Int64>.size {
+                let fast_data_mask: UInt64 = 0x00007ffffffffff8
+                let databits_t: UInt64 = UInt64(self.rodataPointer)
+                return UnsafePointer<UInt32>(bitPattern: UInt(databits_t & fast_data_mask))?.pointee
+            } else {
+                return UnsafePointer<UInt32>(bitPattern: self.rodataPointer & 0xfffffffc)?.pointee
+            }
+        }
+        
+        func class_ro_t() -> UnsafePointer<_class_ro_t>? {
+            if MemoryLayout<Int>.size == MemoryLayout<Int64>.size {
+                let fast_data_mask: UInt64 = 0x00007ffffffffff8
+                let databits_t: UInt64 = UInt64(self.rodataPointer)
+                return UnsafePointer<_class_ro_t>(bitPattern: UInt(databits_t & fast_data_mask))
+            } else {
+                return UnsafePointer<_class_ro_t>(bitPattern: self.rodataPointer & 0xfffffffc)
+            }
+        }
     }
 }
 
@@ -290,11 +324,14 @@ extension Metadata {
                 var name: String?
                 var type: Any.Type?
             }
-            for i in 0..<self.numberOfFields {
+            for i in 0..<self.numberOfFields where fieldRecords[i].mangledTypeName != nil{
                 let name = fieldRecords[i].fieldName
-                if let cMangledTypeName = fieldRecords[i].mangledTypeName,
-                    let fieldType = _getTypeByMangledNameInContext(cMangledTypeName, getMangledTypeNameSize(cMangledTypeName), genericContext: self.contextDescriptorPointer, genericArguments: self.genericArgumentVector) {
-
+                let cMangledTypeName = fieldRecords[i].mangledTypeName!
+                
+                let functionMap: [String: () -> Any.Type?] = [
+                    "function": { _getTypeByMangledNameInContext(cMangledTypeName, getMangledTypeNameSize(cMangledTypeName), genericContext: self.contextDescriptorPointer, genericArguments: self.genericArgumentVector) }
+                ]
+                if let function = functionMap["function"],let fieldType  = function() {
                     result.append(Property.Description(key: name, type: fieldType, offset: fieldOffsets[i]))
                 }
             }