diff --git a/CMakeLists.txt b/CMakeLists.txt
index c286d39e2..96c6b76d5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,7 +3,7 @@ cmake_minimum_required(VERSION 3.20 FATAL_ERROR)
 project(dxtbx LANGUAGES C CXX)
 
 # Add the included modules
-set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules/")
+set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_SOURCE_DIR}/cmake/Modules/")
 
 # General cmake environment configuration
 include(SetDefaultBuildRelWithDebInfo) # Default builds to release with debug info
diff --git a/newsfragments/626.feature b/newsfragments/626.feature
new file mode 100644
index 000000000..c28cc4293
--- /dev/null
+++ b/newsfragments/626.feature
@@ -0,0 +1 @@
+Update Format handling to reflect move of Eiger detector from PETRA P14 to P13.
diff --git a/src/dxtbx/format/FormatCBFMini.py b/src/dxtbx/format/FormatCBFMini.py
index 4561665fd..39060f84a 100644
--- a/src/dxtbx/format/FormatCBFMini.py
+++ b/src/dxtbx/format/FormatCBFMini.py
@@ -8,6 +8,7 @@
 from __future__ import annotations
 
 import binascii
+import datetime
 import os
 import pathlib
 import sys
@@ -73,6 +74,20 @@ def __init__(self, image_file, **kwargs):
         self._raw_data = None
         super().__init__(image_file, **kwargs)
 
+    @staticmethod
+    def _get_timestamp_from_raw_header(
+        header: str | list[str],
+    ) -> datetime.datetime | None:
+        """Given a raw header, or lines from, attempt to extract the timestamp field"""
+        if isinstance(header, str):
+            header = header.splitlines()
+        timestamp = None
+        for record in header:
+            if len(record[1:].split()) <= 2 and record.count(":") == 2:
+                timestamp = datetime.datetime.fromisoformat(record[1:].strip())
+                break
+        return timestamp
+
     def _start(self):
         """Open the image file, read the image header, copy it into a
         dictionary for future reference."""
diff --git a/src/dxtbx/format/FormatCBFMiniEigerPetraP14.py b/src/dxtbx/format/FormatCBFMiniEigerPetraP14.py
index 530948590..36b5cce91 100644
--- a/src/dxtbx/format/FormatCBFMiniEigerPetraP14.py
+++ b/src/dxtbx/format/FormatCBFMiniEigerPetraP14.py
@@ -3,6 +3,7 @@
 
 from __future__ import annotations
 
+import datetime
 import sys
 
 from dxtbx.format.FormatCBFMiniEiger import FormatCBFMiniEiger
@@ -19,11 +20,21 @@ def understand(image_file):
 
         header = FormatCBFMiniEiger.get_cbf_header(image_file)
 
+        # Valid from 22nd May 2021
+        expected_serial = "E-32-0129"
+        if timestamp := FormatCBFMiniEiger._get_timestamp_from_raw_header(header):
+            # We have a timestamp. Let's see what detector we should expect
+
+            # Before 22nd May 2021
+            if timestamp < datetime.datetime(2021, 5, 22):
+                expected_serial = "E-32-0107"
+
+        # Find the line recording detector serial, and check
         for record in header.split("\n"):
             if (
                 "# detector" in record.lower()
                 and "eiger" in record.lower()
-                and "E-32-0107" in record
+                and expected_serial in record
             ):
                 return True