diff --git a/validation/ref/neuron/ball_and_squiggle.py b/validation/ref/neuron/ball_and_squiggle.py
index 258eb5e717221309e68aea0362dcc7e7ad4f21d2..9fcc5b49c5affdb5600437a500f50d8c0f20fb6d 100644
--- a/validation/ref/neuron/ball_and_squiggle.py
+++ b/validation/ref/neuron/ball_and_squiggle.py
@@ -4,7 +4,11 @@
 import json
 import math
 import nrn_validation as V
-from builtins import range
+
+try:
+    from builtins import range
+except ImportError:
+    from __builtin__ import range
 
 V.override_defaults_from_args()
 
diff --git a/validation/ref/neuron/nrn_validation.py b/validation/ref/neuron/nrn_validation.py
index caeb357c0c8ef730b73064781d63a2d4e2ccd863..a924937474c3c7988a87569746da21fa35d01dea 100644
--- a/validation/ref/neuron/nrn_validation.py
+++ b/validation/ref/neuron/nrn_validation.py
@@ -8,7 +8,11 @@ import re
 import numpy as np
 import neuron
 from neuron import h
-from builtins import range
+
+try:
+    from builtins import range
+except ImportError:
+    from __builtin__ import range
 
 # This is super annoying: without neuron.gui, need
 # to explicit load 'standard' hoc routines like 'run',