diff --git a/lib/cmake/modules/ReflectionGenerator.cmake b/lib/cmake/modules/ReflectionGenerator.cmake
index 119f2b5..b80497b 100644
--- a/lib/cmake/modules/ReflectionGenerator.cmake
+++ b/lib/cmake/modules/ReflectionGenerator.cmake
@@ -141,7 +141,7 @@ function (add_reflection_generator_invocation)
     if (ARGS_CLANG_OPTIONS_FROM_TARGETS)
         foreach (TARGET_NAME ${ARGS_CLANG_OPTIONS_FROM_TARGETS})
             # set c++ standard
-            list(APPEND ARGS_CLANG_OPTIONS "-std=c++$<TARGET_PROPERTY:${TARGET_NAME},CXX_STANDARD>")
+            list(APPEND ARGS_CLANG_OPTIONS "$<$<BOOL:$<TARGET_PROPERTY:${TARGET_NAME},CXX_STANDARD>>:-std=c++$<TARGET_PROPERTY:${TARGET_NAME},CXX_STANDARD>>")
             # add compile flags and options
             _reflective_rapidjson_set_prop("${TARGET_NAME}" COMPILE_FLAGS)
             list(APPEND ARGS_CLANG_OPTIONS "$<$<BOOL:${PROP}>:$<JOIN:${PROP},$<SEMICOLON>>>")