--- a/Win32OperatingSystem.st	Thu Jan 12 09:42:50 2017 +0000
+++ b/Win32OperatingSystem.st	Fri Jan 13 23:33:10 2017 +0000
@@ -11986,6 +11986,10 @@
     ^ OSProcessStatus pid:pid status:status code:code core:core
 !
 
+isBlockingOn:fd
+    ^ true
+!
+
 numAvailableForReadOn:fd
     "return the number of bytes available for reading, without blocking."