Add missing const

1 files changed, 1 insertions, 1 deletions

diff --git a/libarchive/test/test_archive_write_set_format_filter_by_ext.c b/libarchive/test/test_archive_write_set_format_filter_by_ext.c
index 4fe18e18..22345038 100644
--- a/libarchive/test/test_archive_write_set_format_filter_by_ext.c
+++ b/libarchive/test/test_archive_write_set_format_filter_by_ext.c
@@ -30,7 +30,7 @@ __FBSDID("$FreeBSD$");
 
 static void
 test_format_filter_by_ext(const char *output_file, 
-    int format_id, int filter_id, int dot_stored, char * def_ext)
+    int format_id, int filter_id, int dot_stored, const char * def_ext)
 {
 	struct archive_entry *ae;
 	struct archive *a;