diff --git a/manual/CHAPTER_Prog/Makefile b/manual/CHAPTER_Prog/Makefile
index 8e326bdc..5c15c6bb 100644
--- a/manual/CHAPTER_Prog/Makefile
+++ b/manual/CHAPTER_Prog/Makefile
@@ -5,7 +5,7 @@ test: stubnets.so
 	tail test1.log test2.log test3.log
 
 stubnets.so: stubnets.cc
-	yosys-config --exec --cxx --cxxflags --ldflags -o $@ -shared $^ --ldlibs
+	yosys-config --exec --cxx --cxxflags -I../.. --ldflags -o $@ -shared $^ --ldlibs
 
 clean:
 	rm -f test1.log test2.log test3.log
diff --git a/manual/PRESENTATION_Prog/Makefile b/manual/PRESENTATION_Prog/Makefile
index 7e3cf814..226b023d 100644
--- a/manual/PRESENTATION_Prog/Makefile
+++ b/manual/PRESENTATION_Prog/Makefile
@@ -5,7 +5,7 @@ CXXFLAGS=$(shell ../../yosys-config --cxxflags)
 DATDIR=$(shell ../../yosys-config --datdir)
 
 my_cmd.so: my_cmd.cc
-	../../yosys-config --exec --cxx $(subst $(DATDIR),../../share,$(CXXFLAGS)) --ldflags -o my_cmd.so -shared my_cmd.cc --ldlibs
+	../../yosys-config --exec --cxx $(subst $(DATDIR),../../share,$(CXXFLAGS)) -I../.. --ldflags -o my_cmd.so -shared my_cmd.cc --ldlibs
 
 test0.log: my_cmd.so
 	../../yosys -Ql test0.log_new -m ./my_cmd.so -p 'my_cmd foo bar' absval_ref.v