diff --git a/notebooks/AGIPD/AGIPD_Correct_and_Verify.ipynb b/notebooks/AGIPD/AGIPD_Correct_and_Verify.ipynb
index e62e407456f015457435690935ff1fd223ca5be8..49bbda86a0f183555114769a7f9167df77f913f1 100644
--- a/notebooks/AGIPD/AGIPD_Correct_and_Verify.ipynb
+++ b/notebooks/AGIPD/AGIPD_Correct_and_Verify.ipynb
@@ -581,7 +581,7 @@
     "    else:\n",
     "        data_units = 'keV'\n",
     "        if photon_energy_warn:\n",
-    "            warning(photon_energy_warn, '. Use 12 keV for lit-pixel counter threshold')\n",
+    "            warning(photon_energy_warn + '. Use 12 keV for lit-pixel counter threshold')\n",
     "            litpx_threshold = 12.\n",
     "        else:\n",
     "            litpx_threshold = photon_energy\n",
@@ -598,7 +598,8 @@
     "    litpx_threshold *= rounding_threshold\n",
     "    print(f\"Count lit-pixels with signal above {litpx_threshold:.3g} {data_units}\")\n",
     "else:\n",
-    "    litpx_threshold = 1e20"
+    "    # dummy value, that is not expected to be used\n",
+    "    litpx_threshold = 42"
    ]
   },
   {