1 files changed, 1 insertions, 1 deletions
diff --git a/git.c b/git.c
index 37b1d76a08..fdb0f71019 100644
--- a/git.c
+++ b/git.c
@@ -286,7 +286,7 @@ static void handle_internal_command(int argc, const char **argv)
 		{ "count-objects", cmd_count_objects, RUN_SETUP },
 		{ "describe", cmd_describe, RUN_SETUP },
 		{ "diff", cmd_diff },
-		{ "diff-files", cmd_diff_files, RUN_SETUP },
+		{ "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
 		{ "diff-index", cmd_diff_index, RUN_SETUP },
 		{ "diff-tree", cmd_diff_tree, RUN_SETUP },
 		{ "fast-export", cmd_fast_export, RUN_SETUP },