diff --git a/ShadowsocksX-NG.xcodeproj/project.pbxproj b/ShadowsocksX-NG.xcodeproj/project.pbxproj
index 8b0ebff..7f97608 100644
--- a/ShadowsocksX-NG.xcodeproj/project.pbxproj
+++ b/ShadowsocksX-NG.xcodeproj/project.pbxproj
@@ -816,6 +816,7 @@
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = macosx;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
+				SWIFT_VERSION = 2.3;
 			};
 			name = Debug;
 		};
@@ -853,6 +854,7 @@
 				MACOSX_DEPLOYMENT_TARGET = 10.10;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = macosx;
+				SWIFT_VERSION = 2.3;
 			};
 			name = Release;
 		};
@@ -925,6 +927,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.qiuyuzhou.ShadowsocksX-NGTests";
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 2.3;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/ShadowsocksX-NG.app/Contents/MacOS/ShadowsocksX-NG";
 			};
 			name = Debug;
@@ -939,6 +942,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "com.qiuyuzhou.ShadowsocksX-NGTests";
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 2.3;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/ShadowsocksX-NG.app/Contents/MacOS/ShadowsocksX-NG";
 			};
 			name = Release;