diff --git a/bolt_unix.go b/bolt_unix.go
index f7d2fe5..95647a7 100644
--- a/bolt_unix.go
+++ b/bolt_unix.go
@@ -1,4 +1,4 @@
-// +build linux darwin
+// +build !windows,!plan9
 
 package bolt
 
diff --git a/bolt_darwin.go b/boltsync_unix.go
similarity index 82%
rename from bolt_darwin.go
rename to boltsync_unix.go
index 6528f72..3c54dd5 100644
--- a/bolt_darwin.go
+++ b/boltsync_unix.go
@@ -1,3 +1,5 @@
+// +build !windows,!plan9,!linux
+
 package bolt
 
 import (