diff --git a/lib/std/os/windows/ws2_32.zig b/lib/std/os/windows/ws2_32.zig
index ea53d621fd98ebde4b6b25986bb5e281495b8abd..12817906c29b89e277bd87a935a6df5fd595ad7d 100644
--- a/lib/std/os/windows/ws2_32.zig
+++ b/lib/std/os/windows/ws2_32.zig
@@ -850,6 +850,8 @@ pub const POLL = struct {
     pub const ERR = 1;
     pub const HUP = 2;
     pub const NVAL = 4;
+    pub const IN = RDNORM | RDBAND;
+    pub const OUT = WRNORM;
 };
 
 pub const TF_DISCONNECT = 1;