diff --git a/Kingfisher.xcodeproj/project.pbxproj b/Kingfisher.xcodeproj/project.pbxproj
index bbee9c752..da883c10d 100644
--- a/Kingfisher.xcodeproj/project.pbxproj
+++ b/Kingfisher.xcodeproj/project.pbxproj
@@ -1001,7 +1001,7 @@
 				SUPPORTED_PLATFORMS = "watchsimulator iphonesimulator appletvsimulator watchos appletvos iphoneos macosx";
 				SWIFT_INSTALL_OBJC_HEADER = NO;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 6.0;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2,3,4";
 				TVOS_DEPLOYMENT_TARGET = 13.0;
 				WATCHOS_DEPLOYMENT_TARGET = 6.0;
@@ -1062,7 +1062,7 @@
 				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_INSTALL_OBJC_HEADER = NO;
 				SWIFT_OPTIMIZATION_LEVEL = "-O";
-				SWIFT_VERSION = 6.0;
+				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2,3,4";
 				TVOS_DEPLOYMENT_TARGET = 13.0;
 				WATCHOS_DEPLOYMENT_TARGET = 6.0;
@@ -1224,7 +1224,6 @@
 				SUPPORTS_XR_DESIGNED_FOR_IPHONE_IPAD = NO;
 				SWIFT_OBJC_BRIDGING_HEADER = "Tests/KingfisherTests/KingfisherTests-Bridging-Header.h";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2,3,4,7";
 			};
 			name = Debug;
@@ -1252,7 +1251,6 @@
 				SWIFT_COMPILATION_MODE = wholemodule;
 				SWIFT_OBJC_BRIDGING_HEADER = "Tests/KingfisherTests/KingfisherTests-Bridging-Header.h";
 				SWIFT_OPTIMIZATION_LEVEL = "-O";
-				SWIFT_VERSION = 5.0;
 				TARGETED_DEVICE_FAMILY = "1,2,3,4,7";
 			};
 			name = Release;