diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8ea944a..9f46c91 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -57,8 +57,7 @@ elseif(${CMAKE_CXX_COMPILER_ID} STREQUAL Clang)
     if (CMAKE_CXX_COMPILER_VERSION VERSION_LESS ${MINIMAL_CLANG})
         message(FATAL_ERROR "Clang ${MINIMAL_CLANG} or higher is required.")
     endif()
-    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE}")
-    set(CMAKE_CXX_FLAGS "-fwhole-program-vtables ${CMAKE_CXX_FLAGS}")
+    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -fwhole-program-vtables -fstrict-vtable-pointers")
 endif()
 
 if (MINGW OR MSVC)