diff --git a/diff.h b/diff.h
index eff4455..7a347cf 100644
--- a/diff.h
+++ b/diff.h
@@ -144,7 +144,9 @@
 			const char *base, const char *path);
 
 extern void diff_unmerge(struct diff_options *,
-			 const char *path);
+			 const char *path,
+			 unsigned mode,
+			 const unsigned char *sha1);
 
 extern int diff_scoreopt_parse(const char *opt);