diff --git a/CoreStore.xcodeproj/project.pbxproj b/CoreStore.xcodeproj/project.pbxproj
index 0950f7f..85ffde7 100644
--- a/CoreStore.xcodeproj/project.pbxproj
+++ b/CoreStore.xcodeproj/project.pbxproj
@@ -2246,6 +2246,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				SDKROOT = iphoneos;
 				SKIP_INSTALL = YES;
+				SWIFT_OPTIMIZATION_LEVEL = "-O";
 				SWIFT_VERSION = 3.0;
 			};
 			name = Release;
@@ -2321,6 +2322,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				SDKROOT = appletvos;
 				SKIP_INSTALL = YES;
+				SWIFT_OPTIMIZATION_LEVEL = "-O";
 				SWIFT_VERSION = 3.0;
 				TARGETED_DEVICE_FAMILY = 3;
 			};
@@ -2404,6 +2406,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/Frameworks";
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
+				SWIFT_OPTIMIZATION_LEVEL = "-O";
 				SWIFT_VERSION = 3.0;
 			};
 			name = Release;
@@ -2486,6 +2489,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				SDKROOT = watchos;
 				SKIP_INSTALL = YES;
+				SWIFT_OPTIMIZATION_LEVEL = "-O";
 				TARGETED_DEVICE_FAMILY = 4;
 			};
 			name = Release;