diff --git a/newsfragments/544.removal b/newsfragments/544.removal
new file mode 100644
index 000000000..7e87901a5
--- /dev/null
+++ b/newsfragments/544.removal
@@ -0,0 +1 @@
+The deprecated ``set_slow_fast_beam_centre_mm`` function has been removed. Please use ``set_fast_slow_beam_centre_mm`` instead.
diff --git a/src/dxtbx/model/detector_helpers.py b/src/dxtbx/model/detector_helpers.py
index 00c648a46..1a8bc0f44 100644
--- a/src/dxtbx/model/detector_helpers.py
+++ b/src/dxtbx/model/detector_helpers.py
@@ -2,7 +2,6 @@
 
 import itertools
 import math
-import warnings
 from operator import itemgetter
 from typing import TYPE_CHECKING, Tuple, cast
 
@@ -175,14 +174,6 @@ def all():
         ]
 
 
-def set_slow_fast_beam_centre_mm(detector, beam, beam_centre, panel_id=None):
-    beam_centre[0], beam_centre[1] = beam_centre[1], beam_centre[0]
-    warnings.warn(
-        "set_slow_fast_beam_centre_mm is deprecated", DeprecationWarning, stacklevel=2
-    )
-    return set_fast_slow_beam_centre_mm(detector, beam, beam_centre, panel_id)
-
-
 def set_fast_slow_beam_centre_mm(detector, beam, beam_centre, panel_id=None):
     """detector and beam are dxtbx objects,
     beam_centre is a tuple of (fast, slow) mm coordinates.