diff --git a/rtengine/histmatching.cc b/rtengine/histmatching.cc
index be618d4d7..3032b36e0 100644
--- a/rtengine/histmatching.cc
+++ b/rtengine/histmatching.cc
@@ -108,7 +108,7 @@ void mappingToCurve(const std::vector<int> &mapping, std::vector<double> &curve)
                 int v = mapping[i];
                 bool change = i > 0 && v != mapping[i-1];
                 int diff = i - prev;
-                if (change && std::abs(diff - step) <= 1) {
+                if ((change && std::abs(diff - step) <= 1) || diff > step * 2) {
                     curve.push_back(coord(i));
                     curve.push_back(coord(v));
                     prev = i;
@@ -117,10 +117,13 @@ void mappingToCurve(const std::vector<int> &mapping, std::vector<double> &curve)
         };
     doit(0, idx, idx > step ? step : idx / 2, true);
     doit(idx, int(mapping.size()), step, idx - step > step / 2);
-    if (curve.size() <= 2 || curve.back() < 0.99 || (1 - curve[curve.size()-2] > step / 512.0 && curve.back() < coord(mapping.back()))) {
-        curve.emplace_back(1.0);
-        curve.emplace_back(1.0);
+    if (curve.size() > 2 && (1 - curve[curve.size()-2] <= step / (256.0 * 3))) {
+        curve.pop_back();
+        curve.pop_back();
     }
+    curve.push_back(1.0);
+    curve.push_back(1.0);
+        
     if (curve.size() < 4) {
         curve = { DCT_Linear }; // not enough points, fall back to linear
     } else {