1 files changed, 1 insertions, 0 deletions

diff --git a/diff.h b/diff.h
index 3a02d38d12..1dfe1f98b1 100644
--- a/diff.h
+++ b/diff.h
@@ -63,6 +63,7 @@ typedef void (*diff_format_fn_t)(struct diff_queue_struct *q,
 #define DIFF_OPT_REVERSE_DIFF        (1 << 15)
 #define DIFF_OPT_CHECK_FAILED        (1 << 16)
 #define DIFF_OPT_RELATIVE_NAME       (1 << 17)
+#define DIFF_OPT_IGNORE_SUBMODULES   (1 << 18)
 #define DIFF_OPT_TST(opts, flag)    ((opts)->flags & DIFF_OPT_##flag)
 #define DIFF_OPT_SET(opts, flag)    ((opts)->flags |= DIFF_OPT_##flag)
 #define DIFF_OPT_CLR(opts, flag)    ((opts)->flags &= ~DIFF_OPT_##flag)