diff --git a/std/c/linux.zig b/std/c/linux.zig
index 9689f61082a6429a33fb8b6c000cc2f760993ea7..a69f3c18b2aedcbdef54adfc85e7aab917f3b7f3 100644
--- a/std/c/linux.zig
+++ b/std/c/linux.zig
@@ -1,9 +1,12 @@
 const std = @import("../std.zig");
+const maxInt = std.math.maxInt;
 usingnamespace std.c;
 
 extern "c" fn __errno_location() *c_int;
 pub const _errno = __errno_location;
 
+pub const MAP_FAILED = @intToPtr(*c_void, maxInt(usize));
+
 pub extern "c" fn getrandom(buf_ptr: [*]u8, buf_len: usize, flags: c_uint) c_int;
 pub extern "c" fn sched_getaffinity(pid: c_int, size: usize, set: *cpu_set_t) c_int;
 pub extern "c" fn eventfd(initval: c_uint, flags: c_uint) c_int;
diff --git a/std/os.zig b/std/os.zig
index 9ca78fa9f31d66156faf46492604f1aa4f3452f1..e9e9c89b4c545267b379120a19d53d9abdaf4d88 100644
--- a/std/os.zig
+++ b/std/os.zig
@@ -1961,7 +1961,7 @@ pub fn mmap(
 ) MMapError![]align(mem.page_size) u8 {
     const err = if (builtin.link_libc) blk: {
         const rc = std.c.mmap(ptr, length, prot, flags, fd, offset);
-        if (rc != MAP_FAILED) return @ptrCast([*]align(mem.page_size) u8, @alignCast(mem.page_size, rc))[0..length];
+        if (rc != std.c.MAP_FAILED) return @ptrCast([*]align(mem.page_size) u8, @alignCast(mem.page_size, rc))[0..length];
         break :blk @intCast(usize, system._errno().*);
     } else blk: {
         const rc = system.mmap(ptr, length, prot, flags, fd, offset);