diff --git a/NPTest.pm b/NPTest.pm
index ebc2602c..b00a7086 100644
--- a/NPTest.pm
+++ b/NPTest.pm
@@ -347,7 +347,7 @@ sub getTestParameter
   }
 
   # Set "none" if no terminal attached (eg, tinderbox build servers when new variables set)
-  return "" unless (-t STDERR);
+  return "" unless (-t STDIN);
 
   my $userResponse = "";