Index: generic/nsf.c
===================================================================
diff -u -r79c263a13be8850014d056153956f5a83dfbb639 -r56b83f4c74bab76211b7a4f6225706f0f54cfa69
--- generic/nsf.c	(.../nsf.c)	(revision 79c263a13be8850014d056153956f5a83dfbb639)
+++ generic/nsf.c	(.../nsf.c)	(revision 56b83f4c74bab76211b7a4f6225706f0f54cfa69)
@@ -11165,7 +11165,7 @@
 
 static int
 ProtectionMatches(Tcl_Interp *interp, int withCallprotection, Tcl_Command cmd) {
-  int result, isProtected = Tcl_Command_flags(cmd) & NSF_CMD_PROTECTED_METHOD;
+  int result, isProtected = (Tcl_Command_flags(cmd) & NSF_CMD_PROTECTED_METHOD) != 0;
   if (withCallprotection == CallprotectionNULL) {
     withCallprotection = CallprotectionPublicIdx;
   }