diff --git a/CMakeLists.txt b/CMakeLists.txt
index b836faad..f566f9d4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -42,7 +42,7 @@ set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_C_STANDARD 11)
 include(GenerateExportHeader)
 set(CMAKE_CXX_FLAGS " -Wall -pedantic -Werror -Wno-deprecated-declarations -D_GLIBCXX_USE_CXX11_ABI=0 -fstack-protector-strong --param=ssp-buffer-size=4 ${CMAKE_CXX_FLAGS}")
-set(CMAKE_CXX_FLAGS_RELEASE "-O3 -D_FORTIFY_SOURCE=2" ${CMAKE_CXX_FLAGS_RELEASE})
+set(CMAKE_CXX_FLAGS_RELEASE " -O3 -D_FORTIFY_SOURCE=2 ${CMAKE_CXX_FLAGS_RELEASE}")
 if(UNIX AND APPLE)
     set(CMAKE_CXX_FLAGS " -stdlib=libc++ ${CMAKE_CXX_FLAGS}")
 endif()