diff --git a/notebooks/DSSC/Characterize_DSSC_Darks_NBC.ipynb b/notebooks/DSSC/Characterize_DSSC_Darks_NBC.ipynb
index fd8d225f55aa1930a85117115d098393989d5125..7d4f3ecfd235c162fc9bfdd5f4ecc9b3c430c9b8 100644
--- a/notebooks/DSSC/Characterize_DSSC_Darks_NBC.ipynb
+++ b/notebooks/DSSC/Characterize_DSSC_Darks_NBC.ipynb
@@ -320,7 +320,7 @@
     "                                                           slow_data_pattern,\n",
     "                                                           slow_data_aggregators,\n",
     "                                                           offset_runs[\"high\"])\n",
-    "except KeyError:\n",
+    "except IOError:\n",
     "    print(\"ERROR: Couldn't access slow data to read tGain, encodedGain, and operatingFreq \\n\")\n",
     "    \n",
     "for gain, mapped_files in gain_mapped_files.items():\n",