diff --git a/object-file.c b/object-file.c
index 8be57f48de..8d645656b7 100644
--- a/object-file.c
+++ b/object-file.c
@@ -2014,7 +2014,7 @@ int write_object_file_flags(const void *buf, unsigned long len,
 	return write_loose_object(oid, hdr, hdrlen, buf, len, 0, flags);
 }
 
-int hash_object_file_literally(const void *buf, unsigned long len,
+int hash_object_file_literally(const void *buf, size_t len,
 			       const char *type, struct object_id *oid,
 			       unsigned flags)
 {
diff --git a/object-store.h b/object-store.h
index 6f89482df0..aa74b4f9b6 100644
--- a/object-store.h
+++ b/object-store.h
@@ -258,7 +258,7 @@ static inline int write_object_file(const void *buf, unsigned long len,
 	return write_object_file_flags(buf, len, type, oid, 0);
 }
 
-int hash_object_file_literally(const void *buf, unsigned long len,
+int hash_object_file_literally(const void *buf, size_t len,
 			       const char *type, struct object_id *oid,
 			       unsigned flags);