diff --git a/diff-lib.c b/diff-lib.c
index c82b07dc1eb47b439bd56f50fb4d07cc8218d22a..1e8215df50e84f6ce191d94ee1c94b336acc7761 100644
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -236,7 +236,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 		old_oid = &ce->oid;
 		new_oid = changed ? &null_oid : &ce->oid;
 		diff_change(&revs->diffopt, oldmode, newmode,
-			    old_oid->hash, new_oid->hash,
+			    old_oid, new_oid,
 			    !is_null_oid(old_oid),
 			    !is_null_oid(new_oid),
 			    ce->name, 0, dirty_submodule);
@@ -367,7 +367,7 @@ static int show_modified(struct rev_info *revs,
 		return 0;
 
 	diff_change(&revs->diffopt, oldmode, mode,
-		    old->oid.hash, oid->hash, 1, !is_null_oid(oid),
+		    &old->oid, oid, 1, !is_null_oid(oid),
 		    old->name, 0, dirty_submodule);
 	return 0;
 }
diff --git a/diff.c b/diff.c
index 3fa335f4464f156b9cfee0837ce400804756de3f..b9bb3f6ca472a7f21e443165651909c7a4606f4a 100644
--- a/diff.c
+++ b/diff.c
@@ -5127,9 +5127,9 @@ void diff_addremove(struct diff_options *options,
 
 void diff_change(struct diff_options *options,
 		 unsigned old_mode, unsigned new_mode,
-		 const unsigned char *old_sha1,
-		 const unsigned char *new_sha1,
-		 int old_sha1_valid, int new_sha1_valid,
+		 const struct object_id *old_oid,
+		 const struct object_id *new_oid,
+		 int old_oid_valid, int new_oid_valid,
 		 const char *concatpath,
 		 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 {
@@ -5142,8 +5142,8 @@ void diff_change(struct diff_options *options,
 
 	if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
 		SWAP(old_mode, new_mode);
-		SWAP(old_sha1, new_sha1);
-		SWAP(old_sha1_valid, new_sha1_valid);
+		SWAP(old_oid, new_oid);
+		SWAP(old_oid_valid, new_oid_valid);
 		SWAP(old_dirty_submodule, new_dirty_submodule);
 	}
 
@@ -5153,8 +5153,8 @@ void diff_change(struct diff_options *options,
 
 	one = alloc_filespec(concatpath);
 	two = alloc_filespec(concatpath);
-	fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
-	fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
+	fill_filespec(one, old_oid->hash, old_oid_valid, old_mode);
+	fill_filespec(two, new_oid->hash, new_oid_valid, new_mode);
 	one->dirty_submodule = old_dirty_submodule;
 	two->dirty_submodule = new_dirty_submodule;
 	p = diff_queue(&diff_queued_diff, one, two);
diff --git a/diff.h b/diff.h
index 1086975a5a68d0487300b232f7ec1a1a80977645..fcf334bb6f6e9c5a4caa0b01c3404e268d7d7f0c 100644
--- a/diff.h
+++ b/diff.h
@@ -23,9 +23,9 @@ typedef int (*pathchange_fn_t)(struct diff_options *options,
 
 typedef void (*change_fn_t)(struct diff_options *options,
 		 unsigned old_mode, unsigned new_mode,
-		 const unsigned char *old_sha1,
-		 const unsigned char *new_sha1,
-		 int old_sha1_valid, int new_sha1_valid,
+		 const struct object_id *old_oid,
+		 const struct object_id *new_oid,
+		 int old_oid_valid, int new_oid_valid,
 		 const char *fullpath,
 		 unsigned old_dirty_submodule, unsigned new_dirty_submodule);
 
@@ -253,10 +253,9 @@ extern void diff_addremove(struct diff_options *,
 
 extern void diff_change(struct diff_options *,
 			unsigned mode1, unsigned mode2,
-			const unsigned char *sha1,
-			const unsigned char *sha2,
-			int sha1_valid,
-			int sha2_valid,
+			const struct object_id *old_oid,
+			const struct object_id *new_oid,
+			int old_oid_valid, int new_oid_valid,
 			const char *fullpath,
 			unsigned dirty_submodule1, unsigned dirty_submodule2);
 
diff --git a/revision.c b/revision.c
index 71519193caa6d6451698be4f3cbcd775e7c9953d..7637e75561971dfa8d45412c999886feb944cab8 100644
--- a/revision.c
+++ b/revision.c
@@ -414,9 +414,9 @@ static void file_add_remove(struct diff_options *options,
 
 static void file_change(struct diff_options *options,
 		 unsigned old_mode, unsigned new_mode,
-		 const unsigned char *old_sha1,
-		 const unsigned char *new_sha1,
-		 int old_sha1_valid, int new_sha1_valid,
+		 const struct object_id *old_oid,
+		 const struct object_id *new_oid,
+		 int old_oid_valid, int new_oid_valid,
 		 const char *fullpath,
 		 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 {
diff --git a/tree-diff.c b/tree-diff.c
index f2c747ea509bf69d7fdadbd16a383e59b2324b2e..7ae1f10b2ee43f82988eef6dbededaad276bfb94 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -74,7 +74,7 @@ static int emit_diff_first_parent_only(struct diff_options *opt, struct combine_
 {
 	struct combine_diff_parent *p0 = &p->parent[0];
 	if (p->mode && p0->mode) {
-		opt->change(opt, p0->mode, p->mode, p0->oid.hash, p->oid.hash,
+		opt->change(opt, p0->mode, p->mode, &p0->oid, &p->oid,
 			1, 1, p->path, 0, 0);
 	}
 	else {