diff --git a/malcolm/modules/pmac/blocks/pmac_trajectory_block.yaml b/malcolm/modules/pmac/blocks/pmac_trajectory_block.yaml
index 3bf41ba3b..3e1e2092b 100644
--- a/malcolm/modules/pmac/blocks/pmac_trajectory_block.yaml
+++ b/malcolm/modules/pmac/blocks/pmac_trajectory_block.yaml
@@ -218,3 +218,9 @@
     description: the version number of the pmac's trajectory program
     rbv: $(pv_prefix):ProgramVersion_RBV
     config: False
+
+- ca.parts.CAChoicePart:
+    name: calculateVelocities
+    description: Does the brick need to calculate the velocity profile
+    pv: $(pv_prefix):ProfileCalcVel
+    config: False
diff --git a/malcolm/modules/pmac/parts/pmactrajectorypart.py b/malcolm/modules/pmac/parts/pmactrajectorypart.py
index acf5581f8..a01605931 100644
--- a/malcolm/modules/pmac/parts/pmactrajectorypart.py
+++ b/malcolm/modules/pmac/parts/pmactrajectorypart.py
@@ -110,9 +110,9 @@ def write_profile(
         z: ADemandTrajectory = None,
     ) -> None:
         child = context.block_view(self.mri)
-
+        child.calculateVelocities.put_value("YES")
         # make sure a matching trajectory program is installed on the pmac
-        if child.trajectoryProgVersion.value != TRAJECTORY_PROGRAM_NUM:
+        if child.trajectoryProgVersion.value < TRAJECTORY_PROGRAM_NUM:
             if child.trajectoryProgVersion.value >= FALLBACK_TRAJ_PROGRAM_NUM:
                 self.log.warning(
                     f"pmac trajectory program is version {FALLBACK_TRAJ_PROGRAM_NUM}"