diff --git a/CMakeLists.txt b/CMakeLists.txt
index f997cea582..5be5819405 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -593,7 +593,7 @@ if (UNIX)
   set( CMAKE_C_FLAGS "-Werror -Wno-pointer-sign -Wall -Wmissing-prototypes -Wmissing-declarations ${CMAKE_C_FLAGS}")
   set( CMAKE_C_FLAGS "-Wno-error=deprecated-declarations -Wno-error=parentheses ${CMAKE_C_FLAGS}")
   set( CMAKE_CXX_FLAGS "-Werror -Wall -Wmissing-declarations -Wno-error=parentheses ${CMAKE_CXX_FLAGS}")
-  set( CMAKE_CXX_FLAGS "-Wno-error=deprecated-declarations ${REGISTER_CXXFLAG} ${CMAKE_CXX_FLAGS}")
+  set( CMAKE_CXX_FLAGS "-Wno-error=deprecated-declarations ${CMAKE_CXX_FLAGS}")
   set( CMAKE_C_FLAGS_RELEASE "-O3 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 ${CMAKE_C_FLAGS}")
 endif()
 if (MINGW)