--- vhdlparser/CMakeLists.txt.orig	2021-05-12 18:46:54 UTC
+++ vhdlparser/CMakeLists.txt
@@ -37,8 +37,8 @@ add_custom_command(
 set_source_files_properties(${GENERATED_SRC}/VhdlParser_adj.cc PROPERTIES GENERATED 1)
 
 include_directories(
-	${PROJECT_SOURCE_DIR}/src
-	${PROJECT_SOURCE_DIR}/vhdlparser
+	BEFORE ${CMAKE_SOURCE_DIR}/src
+	${CMAKE_SOURCE_DIR}/vhdlparser
 	${GENERATED_SRC})
 add_library(vhdlparser STATIC
 CharStream.cc