diff --git a/mmap/mmap_other.go b/mmap/mmap_other.go
index d1b2fe2..c2e0d5b 100644
--- a/mmap/mmap_other.go
+++ b/mmap/mmap_other.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !linux,!windows
+// +build !linux,!windows,!darwin
 
 // Package mmap provides a way to memory-map a file.
 package mmap
diff --git a/mmap/mmap_linux.go b/mmap/mmap_unix.go
similarity index 98%
rename from mmap/mmap_linux.go
rename to mmap/mmap_unix.go
index 57f87ad..4426137 100644
--- a/mmap/mmap_linux.go
+++ b/mmap/mmap_unix.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build linux darwin
+
 // Package mmap provides a way to memory-map a file.
 package mmap