diff --git a/notebooks/AGIPD/AGIPD_Correct_and_Verify.ipynb b/notebooks/AGIPD/AGIPD_Correct_and_Verify.ipynb
index c5d0d966d08817a6f6c0125c7f9e1aea042059c3..cf85b3e52fec533f45f7e7c1590df5069ae289a4 100644
--- a/notebooks/AGIPD/AGIPD_Correct_and_Verify.ipynb
+++ b/notebooks/AGIPD/AGIPD_Correct_and_Verify.ipynb
@@ -41,7 +41,7 @@
     "cal_db_interface = \"tcp://max-exfl-cal001:8015#8045\" # the database interface to use\n",
     "cal_db_timeout = 30000 # in milliseconds\n",
     "creation_date_offset = \"00:00:00\" # add an offset to creation date, e.g. to get different constants\n",
-    "cal_db_root = \"\"  # The calibration database root path to access constant files. e.g. accessing constants from the test database /gpfs/exfel/d/cal/caldb_store.\n",
+    "cal_db_root = \"\"  # The calibration database root path to access constant files. e.g. accessing constants from the test database /gpfs/exfel/d/cal_tst/caldb_store.\n",
     "\n",
     "mem_cells = -1  # Number of memory cells used, set to 0 to automatically infer\n",
     "bias_voltage = -1  # bias voltage, set to 0 to use stored value in slow data.\n",
@@ -612,7 +612,7 @@
     "    gain_setting=gain_setting,\n",
     "    event_at=creation_time,\n",
     "    client=rest_cfg.calibration_client(),\n",
-    "    caldb_root=Path(cal_db_root),\n",
+    "    caldb_root=Path(cal_db_root) if cal_db_root else None,\n",
     ")\n",
     "\n",
     "# Prepare lists of expected calibrations\n",
diff --git a/src/cal_tools/calcat_interface.py b/src/cal_tools/calcat_interface.py
index c1f6c63be031f3ecba0c15aadd71d7b914d61cad..164ce0ee0f52c08a7e1f48f81a2a505f6ab454aa 100644
--- a/src/cal_tools/calcat_interface.py
+++ b/src/cal_tools/calcat_interface.py
@@ -443,7 +443,7 @@ class CalibrationData:
         self.event_at = event_at
         self.pdu_snapshot_at = event_at
         self.module_naming = module_naming
-        if not caldb_root:
+        if caldb_root is None:
             self.caldb_root = self._get_default_caldb_root()
         else:
             self.caldb_root = Path(caldb_root)