diff --git a/tests/qemu-iotests/034 b/tests/qemu-iotests/034
index 69c7858..c769dd8 100755
--- a/tests/qemu-iotests/034
+++ b/tests/qemu-iotests/034
@@ -51,9 +51,13 @@
 echo
 echo "== creating backing file for COW tests =="
 
+TEST_IMG_SAVE="$TEST_IMG"
+TEST_IMG="$TEST_IMG.base"
+
 _make_test_img $size
 $QEMU_IO -c "write -P 0x55 0 1M" "$TEST_IMG" | _filter_qemu_io
-mv "$TEST_IMG" "$TEST_IMG.base"
+
+TEST_IMG="$TEST_IMG_SAVE"
 
 _make_test_img -b "$TEST_IMG.base" 6G