diff --git a/commit.h b/commit.h
index 14f6a5a..048f31e 100644
--- a/commit.h
+++ b/commit.h
@@ -82,6 +82,7 @@
 	const char *after_subject;
 	int preserve_subject;
 	enum date_mode date_mode;
+	unsigned date_mode_explicit:1;
 	int need_8bit_cte;
 	int show_notes;
 	struct reflog_walk_info *reflog_info;