diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 53fc10e73..ae1f9add3 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -17,6 +17,7 @@
 * Twinning is no longer reported when the L-test contradicts it.
 * The `rugnux` report gives the detector tilt and the direct beam beside the beam centre, and carries the tilt in the `dataset_settings` block.
 * The `rugnux` report gives the detector tilt rotation indexing measured, so it can be checked against a powder calibration.
+* `--no-refine-tilt` holds the detector tilt at the value in the file, instead of zeroing it, when the calibration starts from the spots.
 * The `jfjoch_viewer` grid scan view draws the cells in the proportion of the scan steps, so the map has the shape of the scanned area.
 
 ### 1.0.0-rc.165
diff --git a/image_analysis/geom_refinement/PowderCalibration.cpp b/image_analysis/geom_refinement/PowderCalibration.cpp
index 2e4c45604..b583a6a00 100644
--- a/image_analysis/geom_refinement/PowderCalibration.cpp
+++ b/image_analysis/geom_refinement/PowderCalibration.cpp
@@ -295,7 +295,12 @@ CalibrationResult CalibrateFromProfile(const std::vector<float> &profile,
             && (best->uncertainty.sigma_rot1_rad > 0.0 || best->uncertainty.sigma_rot2_rad > 0.0);
     const float significance = tilt_was_free ? TiltSignificance(best->geometry, best->uncertainty) : 0.0f;
     bool tilt_refined = refine_tilt && tilt_was_free && significance >= TILT_MIN_SIGNIFICANCE;
-    if (refine_tilt && !tilt_refined) {
+    // Not `refine_tilt && !tilt_refined`: with --no-refine-tilt the tilt is never free, so
+    // tilt_refined is false and this branch was skipped entirely - leaving the rotations at the ZERO
+    // that GuessInitialGeometry sets, while the CLI reported them as held at the header value. A
+    // declined tilt and a tilt nobody asked to refine both need the header put back and the rest
+    // refitted around it.
+    if (!tilt_refined) {
         // From the header's tilt, not from the one being declined. fit_from now takes a whole geometry,
         // so without this the "pinned" refit would pin rot1/rot2 at exactly the unvalidated values the
         // gate just rejected - which is the same fault the gate exists to catch, reintroduced one level
@@ -346,7 +351,12 @@ CalibrationResult CalibrateFromSpots(const std::vector<SpotToSave> &spots,
             && (unc.sigma_rot1_rad > 0.0 || unc.sigma_rot2_rad > 0.0);
     const float significance = tilt_was_free ? TiltSignificance(fitted, unc) : 0.0f;
     const bool tilt_refined = refine_tilt && tilt_was_free && significance >= TILT_MIN_SIGNIFICANCE;
-    if (refine_tilt && !tilt_refined) {
+    // Not `refine_tilt && !tilt_refined`: with --no-refine-tilt the tilt is never free, so
+    // tilt_refined is false and this branch was skipped entirely - leaving the rotations at the ZERO
+    // that GuessInitialGeometry sets, while the CLI reported them as held at the header value. A
+    // declined tilt and a tilt nobody asked to refine both need the header put back and the rest
+    // refitted around it.
+    if (!tilt_refined) {
         fitted.PoniRot1_rad(geom.GetPoniRot1_rad()).PoniRot2_rad(geom.GetPoniRot2_rad());
         OptimizeGeometry(fitted, spots, calibrant_ring_q, false, &unc);
     }