diff --git a/src/Makefile b/src/Makefile
index 2098184..a508acf 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -54,6 +54,7 @@ libthermo/libthermo.a:
 
 clean:
 	rm -f *.o	
+	rm -f *.P
 	rm -f $(EXEC)
 	$(MAKE) -C libecoPCR clean
 	$(MAKE) -C libecoprimer clean