diff --git a/diff.c b/diff.c
index 9a5c77c13f..4c34c64bd7 100644
--- a/diff.c
+++ b/diff.c
@@ -4308,20 +4308,23 @@ void diff_change(struct diff_options *options,
 		DIFF_OPT_SET(options, HAS_CHANGES);
 }
 
-void diff_unmerge(struct diff_options *options,
-		  const char *path,
-		  unsigned mode, const unsigned char *sha1)
+struct diff_filepair *diff_unmerge(struct diff_options *options,
+				   const char *path,
+				   unsigned mode, const unsigned char *sha1)
 {
+	struct diff_filepair *pair;
 	struct diff_filespec *one, *two;
 
 	if (options->prefix &&
 	    strncmp(path, options->prefix, options->prefix_length))
-		return;
+		return NULL;
 
 	one = alloc_filespec(path);
 	two = alloc_filespec(path);
 	fill_filespec(one, sha1, mode);
-	diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
+	pair = diff_queue(&diff_queued_diff, one, two);
+	pair->is_unmerged = 1;
+	return pair;
 }
 
 static char *run_textconv(const char *pgm, struct diff_filespec *spec,
diff --git a/diff.h b/diff.h
index bf2f44d840..f51a8ee1b2 100644
--- a/diff.h
+++ b/diff.h
@@ -209,7 +209,7 @@ extern void diff_change(struct diff_options *,
 			const char *fullpath,
 			unsigned dirty_submodule1, unsigned dirty_submodule2);
 
-extern void diff_unmerge(struct diff_options *,
+extern struct diff_filepair *diff_unmerge(struct diff_options *,
 			 const char *path,
 			 unsigned mode,
 			 const unsigned char *sha1);