diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7d72ace30..8fc227d0a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,8 +16,8 @@ if (WIN32)
     SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -static-libstdc++ -static-libgcc -static")
 endif (WIN32)
 
-SET(CMAKE_CXX_FLAGS_RELEASE -DRELEASE)
-SET(CMAKE_CXX_FLAGS_DEBUG -DDEBUG)
+SET(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -DRELEASE")
+SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -DDEBUG")
 
 add_executable(ImHex
         source/main.cpp