diff --git a/image_analysis/scale_merge/StillsPartialityRefine.cpp b/image_analysis/scale_merge/StillsPartialityRefine.cpp
index 1df3787c..f01bae07 100644
--- a/image_analysis/scale_merge/StillsPartialityRefine.cpp
+++ b/image_analysis/scale_merge/StillsPartialityRefine.cpp
@@ -326,8 +326,11 @@ double StillsPartialityRefine::RefineOne(IntegrationOutcome &outcome,
 
     // Adopt the refined model only if it correlates with the reference at least as well as the model it
     // replaces. Rejecting puts the crystal back exactly as it arrived, which is the same state a
-    // crystal with too few reflections to fit ends in.
-    if (cc_before.has_value() && std::isfinite(*cc_before) && std::isfinite(cc) && cc < *cc_before) {
+    // crystal with too few reflections to fit ends in. A CC that cannot be measured at all counts as
+    // worse, not as no opinion: ImageReferenceCC returns NaN when too few reflections clear the
+    // partiality cut, which is precisely what a refinement that collapsed the partialities produces -
+    // and adopting it would leave image_scale_cc NaN, on which --min-image-cc drops the image outright.
+    if (cc_before.has_value() && std::isfinite(*cc_before) && !(std::isfinite(cc) && cc >= *cc_before)) {
         for (size_t i = 0; i < outcome.reflections.size(); ++i) {
             outcome.reflections[i].partiality = before[i].first;
             outcome.reflections[i].image_scale_corr = before[i].second;