--- vhdlparser/CMakeLists.txt.orig	2020-11-17 19:19:24 UTC
+++ vhdlparser/CMakeLists.txt
@@ -36,7 +36,7 @@ add_custom_command(
 )
 set_source_files_properties(${GENERATED_SRC}/VhdlParser_adj.cc PROPERTIES GENERATED 1)
 
-include_directories(${PROJECT_SOURCE_DIR}/src ${PROJECT_SOURCE_DIR}/qtools ${PROJECT_SOURCE_DIR}/vhdlparser ${GENERATED_SRC})
+include_directories(BEFORE ${CMAKE_SOURCE_DIR}/src ${CMAKE_SOURCE_DIR}/qtools ${CMAKE_SOURCE_DIR}/vhdlparser ${GENERATED_SRC})
 add_library(vhdlparser STATIC
 CharStream.cc
 ParseException.cc