diff --git a/.gitignore b/.gitignore
index ee4e489..1f2a0f2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@
 *.patch
 *.so
 *~
+*.bak
 *.tab.[ch]
 lex.yy.c
 *.lex.c
diff --git a/tests/Makefile.tests b/tests/Makefile.tests
index f3997e2..cb66c9f 100644
--- a/tests/Makefile.tests
+++ b/tests/Makefile.tests
@@ -49,7 +49,7 @@ TESTS_DEPFILES = $(TESTS:%=%.d) \
 	$(addprefix $(TESTS_PREFIX),testutils.d trees.d dumptrees.d)
 
 TESTS_CLEANFILES_L = $(STD_CLEANFILES) \
-	*.dtb *.test.dts *.test.dt.yaml *.dtsv1 tmp.* \
+	*.dtb *.test.dts *.test.dt.yaml *.dtsv1 tmp.* *.bak \
 	dumptrees
 TESTS_CLEANFILES = $(TESTS) $(TESTS_CLEANFILES_L:%=$(TESTS_PREFIX)%)
 TESTS_CLEANDIRS_L = fs