diff --git a/tsdb/fileutil/mmap_arm64.go b/tsdb/fileutil/mmap_arm64.go
new file mode 100644
index 000000000..4c9534e93
--- /dev/null
+++ b/tsdb/fileutil/mmap_arm64.go
@@ -0,0 +1,19 @@
+// Copyright 2018 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build windows
+// +build windows
+
+package fileutil
+
+const maxMapSize = 0xFFFFFFFFFFFF // 256TB