diff --git a/std/experimental/allocator/mmap_allocator.d b/std/experimental/allocator/mmap_allocator.d
index 3ac22ffff..794355ec9 100644
--- a/std/experimental/allocator/mmap_allocator.d
+++ b/std/experimental/allocator/mmap_allocator.d
@@ -29,10 +29,7 @@ struct MmapAllocator
         {
             import core.sys.posix.sys.mman;
             if (!bytes) return null;
-            version(OSX) import core.sys.osx.sys.mman : MAP_ANON;
-            else version(linux) import core.sys.linux.sys.mman : MAP_ANON;
-            else version(FreeBSD) import core.sys.freebsd.sys.mman : MAP_ANON;
-            else static assert(false, "Add import for MAP_ANON here.");
+            import core.sys.posix.sys : MAP_ANON;
             auto p = mmap(null, bytes, PROT_READ | PROT_WRITE,
                 MAP_PRIVATE | MAP_ANON, -1, 0);
             if (p is MAP_FAILED) return null;