diff --git a/.azure-pipelines/ci-conda-env.txt b/.azure-pipelines/ci-conda-env.txt
index a9ffd554e..5cc5c4fdd 100644
--- a/.azure-pipelines/ci-conda-env.txt
+++ b/.azure-pipelines/ci-conda-env.txt
@@ -2,7 +2,7 @@ conda-forge::boost
 conda-forge::boost-cpp
 conda-forge::bzip2
 conda-forge::c-compiler<1.5
-conda-forge::cctbx-base==2023.5
+conda-forge::cctbx-base==2023.7
 conda-forge::conda
 conda-forge::cxx-compiler<1.5
 conda-forge::python-dateutil
diff --git a/newsfragments/XXX.misc b/newsfragments/XXX.misc
new file mode 100644
index 000000000..57176f832
--- /dev/null
+++ b/newsfragments/XXX.misc
@@ -0,0 +1 @@
+Update prebuilt CI CCTBX version.