diff --git a/cmake/HPX_CompilerFlagsTargets.cmake b/cmake/HPX_CompilerFlagsTargets.cmake
index 5bf4649..0912503 100644
--- a/cmake/HPX_CompilerFlagsTargets.cmake	
+++ b/cmake/HPX_CompilerFlagsTargets.cmake
@@ -15,14 +15,8 @@ target_compile_features(hpx_public_flags INTERFACE cxx_std_${HPX_CXX_STANDARD})
 
 # Set other flags that should always be set
 
-# HPX_DEBUG must be set without a generator expression as it determines ABI
-# compatibility. Projects in Release mode using HPX in Debug mode must have
-# HPX_DEBUG set, and projects in Debug mode using HPX in Release mode must not
-# have HPX_DEBUG set. HPX_DEBUG must also not be set by projects using HPX.
-if(${CMAKE_BUILD_TYPE} STREQUAL "Debug")
-  target_compile_definitions(hpx_private_flags INTERFACE HPX_DEBUG)
-  target_compile_definitions(hpx_public_flags INTERFACE HPX_DEBUG)
-endif()
+target_compile_definitions(hpx_private_flags INTERFACE $<$<CONFIG:DEBUG>:HPX_DEBUG>)
+target_compile_definitions(hpx_public_flags INTERFACE $<$<CONFIG:DEBUG>:HPX_DEBUG>)
 
 target_compile_definitions(
   hpx_private_flags