diff --git a/passes/opt/Makefile.inc b/passes/opt/Makefile.inc
index 42a1d7992..e7b62fc6a 100644
--- a/passes/opt/Makefile.inc
+++ b/passes/opt/Makefile.inc
@@ -40,4 +40,4 @@ passes/opt/peepopt_pm.h: passes/pmgen/pmgen.py $(PEEPOPT_PATTERN)
 	$(P) mkdir -p $(dir $@) && $(PYTHON_EXECUTABLE) $< -o $@ -p peepopt $(filter-out $<,$^)
 endif
 
-include passes/opt/opt_clean/Makefile.inc
\ No newline at end of file
+include $(YOSYS_SRC)/passes/opt/opt_clean/Makefile.inc
\ No newline at end of file