diff --git a/src/interfaces/ecpg/preproc/Makefile b/src/interfaces/ecpg/preproc/Makefile
index d0e3852a878..f2ac8850479 100644
--- a/src/interfaces/ecpg/preproc/Makefile
+++ b/src/interfaces/ecpg/preproc/Makefile
@@ -97,3 +97,4 @@ clean distclean:
 	rm -f *.o ecpg$(X)
 	rm -f typename.c
 	rm -f preproc.y preproc.c preproc.h pgc.c c_kwlist_d.h ecpg_kwlist_d.h
+	rm -rf tmp_check