diff --git a/scripts/rttc.py b/scripts/rttc.py
index f1900543194ad348a718f553dcee111843252ad7..bacfef53c4c588c2325e21107068f110598d1b07 100644
--- a/scripts/rttc.py
+++ b/scripts/rttc.py
@@ -72,6 +72,7 @@ def main():
 
         n_dus = detector.n_dus
         fig, axes = plt.subplots(n_dus, figsize=(16, 4 * n_dus))
+        axes = [axes] if n_dus == 1 else axes.flatten()
         for ax, du in zip(axes, detector.dus):
             times = []
             rttc = []