diff --git a/src/dodal/beamlines/i04_1.py b/src/dodal/beamlines/i04_1.py
index 2341d9a033..c26d27bb63 100644
--- a/src/dodal/beamlines/i04_1.py
+++ b/src/dodal/beamlines/i04_1.py
@@ -123,6 +123,7 @@ def undulator(
         f"{BeamlinePrefix(BL).insertion_prefix}-MO-SERVC-01:",
         wait_for_connection,
         fake_with_ophyd_sim,
+        id_gap_lookup_table_path="SPECIFY_ME",
         bl_prefix=False,
     )
 
diff --git a/src/dodal/beamlines/i22.py b/src/dodal/beamlines/i22.py
index b739b6d4e2..67996435ab 100644
--- a/src/dodal/beamlines/i22.py
+++ b/src/dodal/beamlines/i22.py
@@ -135,7 +135,7 @@ def dcm() -> DoubleCrystalMonochromator:
         d_spacing=(3.13475, "nm"),
     )
     return DoubleCrystalMonochromator(
-        motion_prefix=f"{PREFIX.beamline_prefix}-MO-DCM-01:",
+        prefix=f"{PREFIX.beamline_prefix}-MO-DCM-01:",
         temperature_prefix=f"{PREFIX.beamline_prefix}-DI-DCM-01:",
         crystal_1_metadata=crystal_1_metadata,
         crystal_2_metadata=crystal_2_metadata,
diff --git a/src/dodal/beamlines/p38.py b/src/dodal/beamlines/p38.py
index 11da31b0da..cd02673afc 100644
--- a/src/dodal/beamlines/p38.py
+++ b/src/dodal/beamlines/p38.py
@@ -222,11 +222,10 @@ def dcm(
     return device_instantiation(
         DoubleCrystalMonochromator,
         "dcm",
-        "",
+        f"{BeamlinePrefix(BL).beamline_prefix}-MO-DCM-01:",
         wait_for_connection,
         fake_with_ophyd_sim,
         bl_prefix=False,
-        motion_prefix=f"{BeamlinePrefix(BL).beamline_prefix}-MO-DCM-01:",
         temperature_prefix=f"{BeamlinePrefix(BL).beamline_prefix}-DI-DCM-01:",
         crystal_1_metadata=CrystalMetadata(
             usage="Bragg",
@@ -253,6 +252,7 @@ def undulator(
         f"{BeamlinePrefix(BL).insertion_prefix}-MO-SERVC-01:",
         wait_for_connection,
         fake_with_ophyd_sim,
+        id_gap_lookup_table_path="SPECIFY_ME",
         bl_prefix=False,
         poles=80,
         length=2.0,
diff --git a/src/dodal/devices/i22/dcm.py b/src/dodal/devices/i22/dcm.py
index 682eaa199a..e36e4d545d 100644
--- a/src/dodal/devices/i22/dcm.py
+++ b/src/dodal/devices/i22/dcm.py
@@ -39,7 +39,7 @@ class DoubleCrystalMonochromator(StandardReadable):
 
     def __init__(
         self,
-        motion_prefix: str,
+        prefix: str,
         temperature_prefix: str,
         crystal_1_metadata: CrystalMetadata | None = None,
         crystal_2_metadata: CrystalMetadata | None = None,
@@ -47,13 +47,13 @@ def __init__(
     ) -> None:
         with self.add_children_as_readables():
             # Positionable Parameters
-            self.bragg = Motor(motion_prefix + "BRAGG")
-            self.offset = Motor(motion_prefix + "OFFSET")
-            self.perp = Motor(motion_prefix + "PERP")
-            self.energy = Motor(motion_prefix + "ENERGY")
-            self.crystal_1_roll = Motor(motion_prefix + "XTAL1:ROLL")
-            self.crystal_2_roll = Motor(motion_prefix + "XTAL2:ROLL")
-            self.crystal_2_pitch = Motor(motion_prefix + "XTAL2:PITCH")
+            self.bragg = Motor(prefix + "BRAGG")
+            self.offset = Motor(prefix + "OFFSET")
+            self.perp = Motor(prefix + "PERP")
+            self.energy = Motor(prefix + "ENERGY")
+            self.crystal_1_roll = Motor(prefix + "XTAL1:ROLL")
+            self.crystal_2_roll = Motor(prefix + "XTAL2:ROLL")
+            self.crystal_2_pitch = Motor(prefix + "XTAL2:PITCH")
 
             # Temperatures
             self.backplate_temp = epics_signal_r(float, temperature_prefix + "PT100-7")
diff --git a/tests/devices/i22/test_dcm.py b/tests/devices/i22/test_dcm.py
index fab25936f5..6a7039cb6f 100644
--- a/tests/devices/i22/test_dcm.py
+++ b/tests/devices/i22/test_dcm.py
@@ -19,7 +19,7 @@
 async def dcm() -> DoubleCrystalMonochromator:
     async with DeviceCollector(mock=True):
         dcm = DoubleCrystalMonochromator(
-            motion_prefix="FOO-MO",
+            prefix="FOO-MO",
             temperature_prefix="FOO-DI",
             crystal_1_metadata=CrystalMetadata(
                 usage="Bragg",
@@ -56,7 +56,7 @@ def test_count_dcm(
 async def test_crystal_metadata_not_propagated_when_not_supplied():
     async with DeviceCollector(mock=True):
         dcm = DoubleCrystalMonochromator(
-            motion_prefix="FOO-MO",
+            prefix="FOO-MO",
             temperature_prefix="FOO-DI",
             crystal_1_metadata=None,
             crystal_2_metadata=None,