diff --git a/src/hyperion/external_interaction/ispyb/ispyb_dataclass.py b/src/hyperion/external_interaction/ispyb/ispyb_dataclass.py
index de83bc696..79062fa82 100644
--- a/src/hyperion/external_interaction/ispyb/ispyb_dataclass.py
+++ b/src/hyperion/external_interaction/ispyb/ispyb_dataclass.py
@@ -15,7 +15,6 @@
     "focal_spot_size_x": 0.0,
     "focal_spot_size_y": 0.0,
     "comment": "Descriptive comment.",
-    "undulator_gap": None,
 }
 
 
@@ -32,7 +31,6 @@ class IspybParams(BaseModel):
     sample_id: Optional[str] = None
 
     # Optional from GDA as populated by Ophyd
-    undulator_gap: Optional[float] = None
     xtal_snapshots_omega_start: Optional[list[str]] = None
     xtal_snapshots_omega_end: Optional[list[str]] = None
 
diff --git a/src/hyperion/parameters/components.py b/src/hyperion/parameters/components.py
index 142092d25..efa731615 100644
--- a/src/hyperion/parameters/components.py
+++ b/src/hyperion/parameters/components.py
@@ -244,7 +244,6 @@ class Config:
     beam_size_y: float
     focal_spot_size_x: float
     focal_spot_size_y: float
-    undulator_gap: float | None = None
     xtal_snapshots_omega_start: list[str] | None = None
     xtal_snapshots_omega_end: list[str] | None = None
     xtal_snapshots: list[str] | None = None
diff --git a/src/hyperion/parameters/gridscan.py b/src/hyperion/parameters/gridscan.py
index 09153de99..22e96a34c 100644
--- a/src/hyperion/parameters/gridscan.py
+++ b/src/hyperion/parameters/gridscan.py
@@ -75,7 +75,6 @@ def ispyb_params(self):
             focal_spot_size_y=self.ispyb_extras.focal_spot_size_y,
             comment=self.comment,
             sample_id=str(self.sample_id),
-            undulator_gap=self.ispyb_extras.undulator_gap,
             xtal_snapshots_omega_start=self.ispyb_extras.xtal_snapshots_omega_start
             or [],
             xtal_snapshots_omega_end=self.ispyb_extras.xtal_snapshots_omega_end or [],
diff --git a/src/hyperion/parameters/rotation.py b/src/hyperion/parameters/rotation.py
index 50a6cea6e..9671b8aa9 100644
--- a/src/hyperion/parameters/rotation.py
+++ b/src/hyperion/parameters/rotation.py
@@ -93,7 +93,6 @@ def ispyb_params(self):  # pyright: ignore
             focal_spot_size_y=self.ispyb_extras.focal_spot_size_y,
             comment=self.comment,
             sample_id=str(self.sample_id),
-            undulator_gap=self.ispyb_extras.undulator_gap,
             xtal_snapshots_omega_start=self.ispyb_extras.xtal_snapshots_omega_start,
             xtal_snapshots_omega_end=self.ispyb_extras.xtal_snapshots_omega_end,
             ispyb_experiment_type=self.ispyb_experiment_type,
diff --git a/tests/unit_tests/parameters/test_parameter_model.py b/tests/unit_tests/parameters/test_parameter_model.py
index 6e9e1061f..664b7e348 100644
--- a/tests/unit_tests/parameters/test_parameter_model.py
+++ b/tests/unit_tests/parameters/test_parameter_model.py
@@ -219,7 +219,6 @@ def test_pin_then_xray(self):
                     "current_energy_ev": self.energy,
                     "sample_id": self.sample_id,
                     "visit_path": "/tmp/dls/i03/data/2024/cm66666-6",
-                    "undulator_gap": 0.5,
                     "position": self.position,
                     "beam_size_x": self.beam_size_x,
                     "beam_size_y": self.beam_size_y,
@@ -249,7 +248,6 @@ def test_pin_then_xray(self):
 
         # This should all be stuff that is no longer needed because
         # we get it from devices!
-        old_params.hyperion_params.ispyb_params.undulator_gap = None
         old_params.hyperion_params.ispyb_params.xtal_snapshots_omega_end = []
         old_params.hyperion_params.ispyb_params.xtal_snapshots_omega_start = []
 
@@ -307,7 +305,6 @@ def test_rotation_new_params(self):
                     "current_energy_ev": self.energy,
                     "sample_id": self.sample_id,
                     "visit_path": "/tmp/dls/i03/data/2024/cm66666-6",
-                    "undulator_gap": 0.5,
                     "position": self.position,
                     "beam_size_x": self.beam_size_x,
                     "beam_size_y": self.beam_size_y,
@@ -340,8 +337,4 @@ def test_rotation_new_params(self):
 
         new_old_params = new_params.old_parameters()
 
-        # This should all be stuff that is no longer needed because
-        # we get it from devices!
-        old_params.hyperion_params.ispyb_params.undulator_gap = None
-
         assert new_old_params == old_params