diff --git a/src/droplet_growth/poisson.py b/src/droplet_growth/poisson.py
index 17aba4fed48a3b6eda8be5a74e4b96353a909aaa..14a53ab0790d0323e05f59a59ea65a8680cbba42 100644
--- a/src/droplet_growth/poisson.py
+++ b/src/droplet_growth/poisson.py
@@ -8,7 +8,12 @@ def fit(numbers:np.ndarray, max_value=None, xlabel='Initial number of cells',
         title='', plot=True, save_fig_path=None):
     if max_value is None:
         max_value = numbers.max()
-    bins = np.arange(max_value + 1) - .5
+    try:
+        bins = np.arange(max_value + 1) - .5
+    except ValueError as e:
+        print('poisson error in bins:', *e.args)
+        return None
+
     vector = bins[:-1] +.5
     hist, bins= np.histogram(numbers, bins=bins, density=True)
     popt, pcov = curve_fit(poisson.pmf, vector, hist, p0=(1.,))