diff --git a/internal/nbconn/nbconn_real_non_block_windows.go b/internal/nbconn/nbconn_real_non_block_windows.go
index 3d085dcf..ed1662e0 100644
--- a/internal/nbconn/nbconn_real_non_block_windows.go
+++ b/internal/nbconn/nbconn_real_non_block_windows.go
@@ -24,7 +24,7 @@ var ioctlsocket = dll.MustFindProc("ioctlsocket")
 type sockMode int
 
 const (
-	FIONBIO             int      = 0x8004667e
+	FIONBIO             uint32   = 0x8004667e
 	sockModeBlocking    sockMode = 0
 	sockModeNonBlocking sockMode = 1
 )