diff --git a/Makefile b/Makefile
index b282dc6c6..8f02329bc 100644
--- a/Makefile
+++ b/Makefile
@@ -790,7 +790,7 @@ LDLIBS_NOVERIFIC = $(LDLIBS)
 endif
 
 $(PROGRAM_PREFIX)yosys-config: misc/yosys-config.in
-	$(P) $(SED) -e 's#@CXXFLAGS@#$(subst -Ilibs/dlfcn-win32,,$(subst -I. -I"$(YOSYS_SRC)",-I"$(DATDIR)/include",$(strip $(CXXFLAGS_NOVERIFIC))))#;' \
+	$(P) $(SED) -e 's#@CXXFLAGS@#$(subst -Ilibs/dlfcn-win32,,$(subst -I. -I"$(YOSYS_SRC)",-I"$(PREFIX)/include/yosys",$(strip $(CXXFLAGS_NOVERIFIC))))#;' \
 			-e 's#@CXX@#$(strip $(CXX))#;' -e 's#@LDFLAGS@#$(strip $(LDFLAGS) $(PLUGIN_LDFLAGS))#;' -e 's#@LDLIBS@#$(strip $(LDLIBS_NOVERIFIC) $(PLUGIN_LDLIBS))#;' \
 			-e 's#@BINDIR@#$(strip $(BINDIR))#;' -e 's#@DATDIR@#$(strip $(DATDIR))#;' < $< > $(PROGRAM_PREFIX)yosys-config
 	$(Q) chmod +x $(PROGRAM_PREFIX)yosys-config
diff --git a/tests/various/plugin.sh b/tests/various/plugin.sh
index 2880c8c06..a32f11a13 100644
--- a/tests/various/plugin.sh
+++ b/tests/various/plugin.sh
@@ -3,6 +3,6 @@ rm -f plugin.so
 CXXFLAGS=$(../../yosys-config --cxxflags)
 DATDIR=$(../../yosys-config --datdir)
 DATDIR=${DATDIR//\//\\\/}
-CXXFLAGS=${CXXFLAGS//$DATDIR/..\/..\/share}
+CXXFLAGS=${CXXFLAGS//\/usr\/include\/yosys/..\/..\/share\/include}
 ../../yosys-config --exec --cxx ${CXXFLAGS} --ldflags -shared -o plugin.so plugin.cc
 ../../yosys -m ./plugin.so -p "test" | grep -q "Plugin test passed!"