diff --git a/notebooks/ePix/Characterize_Darks_ePix_NBC.ipynb b/notebooks/ePix/Characterize_Darks_ePix_NBC.ipynb
index 660e35df8d12a3fc9320efafbc3cfe760c9d2168..c4cfcd1045997035df6ea9c3199017fae6056ea4 100644
--- a/notebooks/ePix/Characterize_Darks_ePix_NBC.ipynb
+++ b/notebooks/ePix/Characterize_Darks_ePix_NBC.ipynb
@@ -381,7 +381,7 @@
     "    # specify the a version for this constant\n",
     "    if use_dir_creation_date:\n",
     "        metadata.calibration_constant_version = Versions.FromFile(device=device,\n",
-    "                                                                  file_path= filename)\n",
+    "                                                                  file_path= ped_dir)\n",
     "    else:\n",
     "        metadata.calibration_constant_version = Versions.Now(device=device)\n",
     "        \n",