diff --git a/SWXMLHash.xcodeproj/project.pbxproj b/SWXMLHash.xcodeproj/project.pbxproj
index 3579d1ac..5dc1c191 100644
--- a/SWXMLHash.xcodeproj/project.pbxproj
+++ b/SWXMLHash.xcodeproj/project.pbxproj
@@ -766,7 +766,7 @@
 				SDKROOT = iphoneos;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
 				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VERSIONING_SYSTEM = "apple-generic";
 				VERSION_INFO_PREFIX = "";
@@ -820,7 +820,7 @@
 				SDKROOT = iphoneos;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
 				SWIFT_SWIFT3_OBJC_INFERENCE = Default;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = "1,2";
 				VALIDATE_PRODUCT = YES;
 				VERSIONING_SYSTEM = "apple-generic";
@@ -942,7 +942,7 @@
 				PRODUCT_NAME = SWXMLHash;
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -969,7 +969,7 @@
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Release;
 		};
@@ -992,7 +992,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "drmohundro.${PRODUCT_NAME:rfc1034identifier}";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = macosx;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Debug;
 		};
@@ -1013,7 +1013,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = macosx;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 			};
 			name = Release;
 		};
@@ -1035,7 +1035,7 @@
 				PRODUCT_NAME = SWXMLHash;
 				SDKROOT = appletvos;
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = 3;
 				TVOS_DEPLOYMENT_TARGET = 9.0;
 			};
@@ -1061,7 +1061,7 @@
 				SDKROOT = appletvos;
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = 3;
 				TVOS_DEPLOYMENT_TARGET = 9.0;
 			};
@@ -1079,7 +1079,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "drmohundro.SWXMLHash-tvOS-Tests";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = appletvos;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TVOS_DEPLOYMENT_TARGET = 9.0;
 			};
 			name = Debug;
@@ -1098,7 +1098,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SDKROOT = appletvos;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TVOS_DEPLOYMENT_TARGET = 9.0;
 			};
 			name = Release;
@@ -1121,7 +1121,7 @@
 				PRODUCT_NAME = SWXMLHash;
 				SDKROOT = watchos;
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = 4;
 				WATCHOS_DEPLOYMENT_TARGET = 2.0;
 			};
@@ -1147,7 +1147,7 @@
 				SDKROOT = watchos;
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
-				SWIFT_VERSION = 3.0;
+				SWIFT_VERSION = 4.0;
 				TARGETED_DEVICE_FAMILY = 4;
 				WATCHOS_DEPLOYMENT_TARGET = 2.0;
 			};