--- libmalloc/libmalloc-374.60.3/xcodeconfig/libmalloc_xctests.xcconfig
+++ libmalloc/libmalloc-474.0.13/xcodeconfig/libmalloc_xctests.xcconfig
@@ -5,7 +5,7 @@
 INFOPLIST_FILE = tests/xctests/Info.plist
 PRODUCT_BUNDLE_IDENTIFIER = com.apple.libmalloc-xctests
 
-OTHER_CFLAGS = -fno-builtin
+OTHER_CFLAGS = -fno-builtin -fno-typed-memory-operations
 OTHER_LDFLAGS = -framework Foundation -lCrashReporterClient
 
 CLANG_ENABLE_OBJC_ARC = YES
@@ -18,3 +18,5 @@
 
 XCODE_SIGN_IDENTITY = -
 CODE_SIGN_IDENTITY = -
+
+GCC_PREPROCESSOR_DEFINITIONS = MALLOC_BUILDING_XCTESTS