diff --git a/disk_postprocess.py b/disk_postprocess.py
index 2dd2045..62323b0 100644
--- a/disk_postprocess.py
+++ b/disk_postprocess.py
@@ -929,7 +929,7 @@ def disk_pdf(
     P.xlabel(r"$\log(N / \bar{N})$")
     P.ylabel("Probability density")
     P.title(title)
-    P.hist(dcoldens, nb_bins_hist, range=(-1, 2))
+    P.hist(dcoldens, nb_bin_hist, range=(-1, 2))
 
     if interactive:
         pass