diff --git a/code/CMakeLists.txt b/code/CMakeLists.txt
index 6e2db91db..dafe017ef 100644
--- a/code/CMakeLists.txt
+++ b/code/CMakeLists.txt
@@ -485,9 +485,9 @@ ADD_ASSIMP_IMPORTER( IFC
 )
 if (ASSIMP_BUILD_IFC_IMPORTER)
   if (MSVC)
-    set_source_files_properties(IFCReaderGen1.cpp IFCReaderGen2.cpp PROPERTIES COMPILE_FLAGS "/bigobj")
+    set_source_files_properties(Importer/IFC/IFCReaderGen1_2x3.cpp Importer/IFC/IFCReaderGen2_2x3.cpp PROPERTIES COMPILE_FLAGS "/bigobj")
   elseif(CMAKE_COMPILER_IS_MINGW)
-    set_source_files_properties(IFCReaderGen1.cpp IFCReaderGen2.cpp PROPERTIES COMPILE_FLAGS "-O2 -Wa,-mbig-obj")
+    set_source_files_properties(Importer/IFC/IFCReaderGen1_2x3.cpp Importer/IFC/IFCReaderGen2_2x3.cpp PROPERTIES COMPILE_FLAGS "-O2 -Wa,-mbig-obj")
   endif()
 endif (ASSIMP_BUILD_IFC_IMPORTER)