diff --git a/.github/workflows/python-publish.yml b/.github/workflows/python-publish.yml
index 5ba8147..095269d 100644
--- a/.github/workflows/python-publish.yml
+++ b/.github/workflows/python-publish.yml
@@ -29,7 +29,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install setuptools wheel twine
+        pip install setuptools wheel twine pandas
         # pip install build
     - name: Build and publish package
       env:
diff --git a/import_serial/import_serial.py b/import_serial/import_serial.py
index 58a4e4d..2af0fae 100644
--- a/import_serial/import_serial.py
+++ b/import_serial/import_serial.py
@@ -10,8 +10,11 @@
 import pandas as pd
 from math import sqrt
 import json
-from cctbx import miller, crystal, uctbx, sgtbx, xray
-from cctbx.array_family import flex
+try:
+    from cctbx import miller, crystal, uctbx, sgtbx, xray
+    from cctbx.array_family import flex
+except ModuleNotFoundError:
+    print("WARNING: ModuleNotFoundError: Module CCTBX was not found.")
 # TO DO: 3 input files
 # TO DO: unit cell parameters from stream file
 # TO DO: check output MTZ