Index: compiler-rt/lib/fuzzer/tests/CMakeLists.txt
===================================================================
--- compiler-rt/lib/fuzzer/tests/CMakeLists.txt
+++ compiler-rt/lib/fuzzer/tests/CMakeLists.txt
@@ -22,7 +22,7 @@
 endif()
 
 if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux" AND COMPILER_RT_LIBCXX_PATH)
-  list(APPEND LIBFUZZER_UNITTEST_CFLAGS -nostdinc++ -D_LIBCPP_ABI_VERSION=Fuzzer)
+  list(APPEND LIBFUZZER_UNITTEST_CFLAGS -nostdinc++)
 endif()
 
 if(COMPILER_RT_DEFAULT_TARGET_ARCH IN_LIST FUZZER_SUPPORTED_ARCH)
@@ -45,7 +45,7 @@
 
   if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux" AND COMPILER_RT_LIBCXX_PATH)
     set(LIBFUZZER_TEST_RUNTIME_DEPS libcxx_fuzzer_${arch}-build)
-    set(LIBFUZZER_TEST_RUNTIME_CFLAGS -isystem ${COMPILER_RT_LIBCXX_PATH}/include)
+    set(LIBFUZZER_TEST_RUNTIME_CFLAGS -isystem ${LIBCXX_${arch}_PREFIX}/include/c++/v1)
     set(LIBFUZZER_TEST_RUNTIME_LINK_FLAGS ${LIBCXX_${arch}_PREFIX}/lib/libc++.a)
   endif()