diff --git a/CleanroomLogger.xcodeproj/project.pbxproj b/CleanroomLogger.xcodeproj/project.pbxproj
index 68dd44c5..960b55d8 100644
--- a/CleanroomLogger.xcodeproj/project.pbxproj
+++ b/CleanroomLogger.xcodeproj/project.pbxproj
@@ -306,18 +306,19 @@
 			isa = PBXProject;
 			attributes = {
 				LastSwiftUpdateCheck = 0800;
-				LastUpgradeCheck = 0820;
+				LastUpgradeCheck = 0900;
 				ORGANIZATIONNAME = "Gilt Groupe";
 				TargetAttributes = {
 					3B9059021DAECB5200B4EEC0 = {
 						CreatedOnToolsVersion = 8.0;
 						DevelopmentTeam = MTP6A36P8K;
+						LastSwiftMigration = 0900;
 						ProvisioningStyle = Automatic;
 					};
 					3B90590B1DAECB5200B4EEC0 = {
 						CreatedOnToolsVersion = 8.0;
 						DevelopmentTeam = MTP6A36P8K;
-						LastSwiftMigration = 0820;
+						LastSwiftMigration = 0900;
 						ProvisioningStyle = Automatic;
 					};
 				};
@@ -441,7 +442,9 @@
 				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_DOCUMENTATION_COMMENTS = YES;
@@ -449,7 +452,11 @@
 				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_SUSPICIOUS_MOVES = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
@@ -492,7 +499,9 @@
 				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_DOCUMENTATION_COMMENTS = YES;
@@ -500,7 +509,11 @@
 				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_SUSPICIOUS_MOVES = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
@@ -536,7 +549,7 @@
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -550,7 +563,7 @@
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Release;
 		};
@@ -562,7 +575,7 @@
 				CLANG_ENABLE_MODULES = YES;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -574,7 +587,7 @@
 				CLANG_ENABLE_MODULES = YES;
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Release;
 		};
diff --git a/CleanroomLogger.xcodeproj/xcshareddata/xcschemes/CleanroomLogger.xcscheme b/CleanroomLogger.xcodeproj/xcshareddata/xcschemes/CleanroomLogger.xcscheme
index a4a48a83..2f4b0eb1 100644
--- a/CleanroomLogger.xcodeproj/xcshareddata/xcschemes/CleanroomLogger.xcscheme
+++ b/CleanroomLogger.xcodeproj/xcshareddata/xcschemes/CleanroomLogger.xcscheme
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0820"
+   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>
          <TestableReference
@@ -55,6 +56,7 @@
       buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      language = ""
       launchStyle = "0"
       useCustomWorkingDirectory = "NO"
       ignoresPersistentStateOnLaunch = "NO"