diff --git a/nettypes.h b/nettypes.h
index 632a63e41..d532c24e9 100644
--- a/nettypes.h
+++ b/nettypes.h
@@ -48,7 +48,7 @@ class netrange_t {
       { msb_ = that.msb_; lsb_ = that.lsb_; return *this; }
 
       inline bool defined() const
-      { return msb_!=LONG_MAX || msb_!= LONG_MAX; }
+      { return msb_!=LONG_MAX || lsb_!= LONG_MAX; }
 
       inline unsigned long width()const
       { if (!defined()) return 0;