diff --git a/Rx.xcodeproj/project.pbxproj b/Rx.xcodeproj/project.pbxproj
index 144a26ef..5bf29160 100644
--- a/Rx.xcodeproj/project.pbxproj
+++ b/Rx.xcodeproj/project.pbxproj
@@ -5258,6 +5258,7 @@
 				ENABLE_BITCODE = YES;
 				ENABLE_NS_ASSERTIONS = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
+				ENABLE_TESTABILITY = YES;
 				GCC_C_LANGUAGE_STANDARD = gnu99;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_PREPROCESSOR_DEFINITIONS = "TRACE_RESOURCES=1";
@@ -5714,6 +5715,7 @@
 				ENABLE_BITCODE = YES;
 				ENABLE_NS_ASSERTIONS = NO;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
+				ENABLE_TESTABILITY = YES;
 				GCC_C_LANGUAGE_STANDARD = gnu99;
 				GCC_NO_COMMON_BLOCKS = YES;
 				GCC_TREAT_WARNINGS_AS_ERRORS = YES;