diff --git a/CMakeLists.txt b/CMakeLists.txt
index aec5eb993..dc4546691 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -19,15 +19,11 @@ option (IMGUI_IMPL_DX12 "Build the DirectX 12 implementation (only if supported)
 
 set (CMAKE_CXX_STANDARD 11)
 
-if (IMGUI_DEMO)
-    set (IMGUI_DEMO_SRC imgui_demo.cpp)
-endif ()
-
 add_library (imgui STATIC
     imgui.cpp
     imgui_draw.cpp
     imgui_widgets.cpp
-    ${IMGUI_DEMO_SRC}
+    $<$<BOOL:IMGUI_DEMO>:imgui_demo.cpp>
 )
 
 target_include_directories (imgui PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}")