diff --git a/Framework/MASPreferencesViewController.h b/Framework/MASPreferencesViewController.h
index 0ff861e..7704923 100644
--- a/Framework/MASPreferencesViewController.h
+++ b/Framework/MASPreferencesViewController.h
@@ -6,6 +6,10 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
+#if !defined(NSUserInterfaceItemIdentifier)
+typedef NSString * NSUserInterfaceItemIdentifier NS_EXTENSIBLE_STRING_ENUM;
+#endif
+
 /*!
  * Requirements for the Preferences panel
  */
@@ -14,7 +18,7 @@ NS_ASSUME_NONNULL_BEGIN
 /*!
  * Unique identifier of the Panel represented by the view controller.
  */
-@property (nonatomic, readonly, nullable) NSString *identifier;
+@property (nonatomic, readonly, nullable) NSUserInterfaceItemIdentifier identifier;
 
 /*!
  * Toolbar icon for the Panel represented by the view controller.
diff --git a/MASPreferences.xcodeproj/project.pbxproj b/MASPreferences.xcodeproj/project.pbxproj
index a02c8e1..b24f55d 100644
--- a/MASPreferences.xcodeproj/project.pbxproj
+++ b/MASPreferences.xcodeproj/project.pbxproj
@@ -106,7 +106,7 @@
 		F16AF7EB1BA279F10022155C /* Project object */ = {
 			isa = PBXProject;
 			attributes = {
-				LastUpgradeCheck = 0800;
+				LastUpgradeCheck = 0900;
 				ORGANIZATIONNAME = "Vadim Shpakovski";
 				TargetAttributes = {
 					F16AF7F31BA279F10022155C = {
@@ -173,14 +173,20 @@
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_ENABLE_OBJC_ARC = YES;
+				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
+				CLANG_WARN_COMMA = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
 				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
 				CLANG_WARN_EMPTY_BODY = YES;
 				CLANG_WARN_ENUM_CONVERSION = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
 				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
+				CLANG_WARN_STRICT_PROTOTYPES = YES;
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
@@ -217,14 +223,20 @@
 				CLANG_CXX_LIBRARY = "libc++";
 				CLANG_ENABLE_MODULES = YES;
 				CLANG_ENABLE_OBJC_ARC = YES;
+				CLANG_WARN_BLOCK_CAPTURE_AUTORELEASING = YES;
 				CLANG_WARN_BOOL_CONVERSION = YES;
+				CLANG_WARN_COMMA = YES;
 				CLANG_WARN_CONSTANT_CONVERSION = YES;
 				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
 				CLANG_WARN_EMPTY_BODY = YES;
 				CLANG_WARN_ENUM_CONVERSION = YES;
 				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_INT_CONVERSION = YES;
+				CLANG_WARN_NON_LITERAL_NULL_CONVERSION = YES;
+				CLANG_WARN_OBJC_LITERAL_CONVERSION = YES;
 				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_RANGE_LOOP_ANALYSIS = YES;
+				CLANG_WARN_STRICT_PROTOTYPES = YES;
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
diff --git a/MASPreferences.xcodeproj/xcshareddata/xcschemes/MASPreferences.xcscheme b/MASPreferences.xcodeproj/xcshareddata/xcschemes/MASPreferences.xcscheme
index 758b595..070ec71 100644
--- a/MASPreferences.xcodeproj/xcshareddata/xcschemes/MASPreferences.xcscheme
+++ b/MASPreferences.xcodeproj/xcshareddata/xcschemes/MASPreferences.xcscheme
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0800"
+   LastUpgradeVersion = "0900"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
@@ -26,6 +26,7 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
       shouldUseLaunchSchemeArgsEnv = "YES">
       <Testables>
       </Testables>
@@ -36,6 +37,7 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
       launchStyle = "0"
       useCustomWorkingDirectory = "NO"
       ignoresPersistentStateOnLaunch = "NO"