diff --git a/interp/tools.py b/interp/tools.py
index eceb168..e5e2f75 100644
--- a/interp/tools.py
+++ b/interp/tools.py
@@ -51,7 +51,8 @@ def friendly_exact_3D(X):
 
 def improved_answer(answer, exact):
   if not answer['error']:
-    return True
+    # was probably just a linear interpolation
+    return False
 
   log.debug('qlin:  %s' % answer['qlin'])
   log.debug('error: %s' % answer['error'])