diff --git a/include/git2/odb_backend.h b/include/git2/odb_backend.h
index d004238a4..5696ee07d 100644
--- a/include/git2/odb_backend.h
+++ b/include/git2/odb_backend.h
@@ -75,7 +75,7 @@ struct git_odb_stream {
 
 	int (*read)(git_odb_stream *stream, char *buffer, size_t len);
 	int (*write)(git_odb_stream *stream, const char *buffer, size_t len);
-	int (*finalize_write)(git_oid *oid_p, git_odb_stream *stream);
+	int (*finalize_write)(git_odb_stream *stream, const git_oid *oid);
 	void (*free)(git_odb_stream *stream);
 };
 
diff --git a/include/git2/sys/odb_backend.h b/include/git2/sys/odb_backend.h
index 3cd2734c0..2d06613d2 100644
--- a/include/git2/sys/odb_backend.h
+++ b/include/git2/sys/odb_backend.h
@@ -48,12 +48,8 @@ struct git_odb_backend {
 	int (* read_header)(
 		size_t *, git_otype *, git_odb_backend *, const git_oid *);
 
-	/* The writer may assume that the object
-	 * has already been hashed and is passed
-	 * in the first parameter.
-	 */
 	int (* write)(
-		git_oid *, git_odb_backend *, const void *, size_t, git_otype);
+		git_odb_backend *, const git_oid *, const void *, size_t, git_otype);
 
 	int (* writestream)(
 		git_odb_stream **, git_odb_backend *, size_t, git_otype);
diff --git a/src/odb.c b/src/odb.c
index b7f64dfc9..d2be60f97 100644
--- a/src/odb.c
+++ b/src/odb.c
@@ -291,10 +291,10 @@ typedef struct {
 	git_otype type;
 } fake_wstream;
 
-static int fake_wstream__fwrite(git_oid *oid, git_odb_stream *_stream)
+static int fake_wstream__fwrite(git_odb_stream *_stream, const git_oid *oid)
 {
 	fake_wstream *stream = (fake_wstream *)_stream;
-	return _stream->backend->write(oid, _stream->backend, stream->buffer, stream->size, stream->type);
+	return _stream->backend->write(_stream->backend, oid, stream->buffer, stream->size, stream->type);
 }
 
 static int fake_wstream__write(git_odb_stream *_stream, const char *data, size_t len)
@@ -851,7 +851,7 @@ int git_odb_write(
 			continue;
 
 		if (b->write != NULL)
-			error = b->write(oid, b, data, len, type);
+			error = b->write(b, oid, data, len, type);
 	}
 
 	if (!error || error == GIT_PASSTHROUGH)
@@ -931,7 +931,7 @@ int git_odb_stream_write(git_odb_stream *stream, const char *buffer, size_t len)
 int git_odb_stream_finalize_write(git_oid *out, git_odb_stream *stream)
 {
 	git_hash_final(out, stream->hash_ctx);
-	return stream->finalize_write(out, stream);
+	return stream->finalize_write(stream, out);
 }
 
 int git_odb_stream_read(git_odb_stream *stream, char *buffer, size_t len)
diff --git a/src/odb_loose.c b/src/odb_loose.c
index 35f53fb7d..d1ca18edb 100644
--- a/src/odb_loose.c
+++ b/src/odb_loose.c
@@ -769,7 +769,7 @@ static int loose_backend__foreach(git_odb_backend *_backend, git_odb_foreach_cb
 	return state.cb_error ? state.cb_error : error;
 }
 
-static int loose_backend__stream_fwrite(git_oid *oid, git_odb_stream *_stream)
+static int loose_backend__stream_fwrite(git_odb_stream *_stream, const git_oid *oid)
 {
 	loose_writestream *stream = (loose_writestream *)_stream;
 	loose_backend *backend = (loose_backend *)_stream->backend;
@@ -850,7 +850,7 @@ static int loose_backend__stream(git_odb_stream **stream_out, git_odb_backend *_
 	return !stream ? -1 : 0;
 }
 
-static int loose_backend__write(git_oid *oid, git_odb_backend *_backend, const void *data, size_t len, git_otype type)
+static int loose_backend__write(git_odb_backend *_backend, const git_oid *oid, const void *data, size_t len, git_otype type)
 {
 	int error = 0, header_len;
 	git_buf final_path = GIT_BUF_INIT;