diff --git a/rtengine/histmatching.cc b/rtengine/histmatching.cc
index 71bdffc58..5b7647f49 100644
--- a/rtengine/histmatching.cc
+++ b/rtengine/histmatching.cc
@@ -139,6 +139,14 @@ void RawImageSource::getAutoMatchedToneCurve(std::vector<double> &outCurve)
         std::cout << "performing histogram matching for " << getFileName() << " on the embedded thumbnail" << std::endl;
     }
 
+    if (!histMatchingCache.empty()) {
+        if (settings->verbose) {
+            std::cout << "tone curve found in cache" << std::endl;
+            outCurve = histMatchingCache;
+            return;
+        }
+    }
+
     outCurve = { DCT_Linear };
 
     int fw, fh;
@@ -161,6 +169,7 @@ void RawImageSource::getAutoMatchedToneCurve(std::vector<double> &outCurve)
             if (settings->verbose) {
                 std::cout << "histogram matching: no thumbnail found, generating a neutral curve" << std::endl;
             }
+            histMatchingCache = outCurve;
             return;
         }
         source.reset(thumb->quickProcessImage(neutral, fh / skip, TI_Nearest));
@@ -233,6 +242,8 @@ void RawImageSource::getAutoMatchedToneCurve(std::vector<double> &outCurve)
     if (settings->verbose) {
         std::cout << "histogram matching: generated curve with " << outCurve.size()/2 << " control points" << std::endl;
     }
+
+    histMatchingCache = outCurve;
 }
 
 } // namespace rtengine
diff --git a/rtengine/improccoordinator.cc b/rtengine/improccoordinator.cc
index 75fc81e9f..d390d94ca 100644
--- a/rtengine/improccoordinator.cc
+++ b/rtengine/improccoordinator.cc
@@ -449,7 +449,7 @@ void ImProcCoordinator::updatePreviewImage (int todo, Crop* cropCall)
         if (params.toneCurve.histmatching) {
             imgsrc->getAutoMatchedToneCurve(params.toneCurve.curve);
 
-            params.toneCurve.histmatching = false;
+            params.toneCurve.autoexp = false;
             params.toneCurve.curveMode = ToneCurveParams::TcMode::FILMLIKE;
             params.toneCurve.curve2 = { 0 };
             params.toneCurve.expcomp = 0.0;
diff --git a/rtengine/rawimagesource.h b/rtengine/rawimagesource.h
index a199eb13a..59316eccf 100644
--- a/rtengine/rawimagesource.h
+++ b/rtengine/rawimagesource.h
@@ -95,6 +95,7 @@ protected:
     float psGreenBrightness[4];
     float psBlueBrightness[4];
 
+    std::vector<double> histMatchingCache;
 
     void hphd_vertical       (float** hpmap, int col_from, int col_to);
     void hphd_horizontal     (float** hpmap, int row_from, int row_to);
diff --git a/rtengine/simpleprocess.cc b/rtengine/simpleprocess.cc
index 0bd784e45..0cc223da1 100644
--- a/rtengine/simpleprocess.cc
+++ b/rtengine/simpleprocess.cc
@@ -743,7 +743,7 @@ private:
         if (params.toneCurve.histmatching) {
             imgsrc->getAutoMatchedToneCurve(params.toneCurve.curve);
 
-            params.toneCurve.histmatching = false;
+            params.toneCurve.autoexp = false;
             params.toneCurve.curveMode = ToneCurveParams::TcMode::FILMLIKE;
             params.toneCurve.curve2 = { 0 };
             params.toneCurve.expcomp = 0.0;
diff --git a/rtgui/tonecurve.cc b/rtgui/tonecurve.cc
index 0d753dcbf..4a25794ff 100644
--- a/rtgui/tonecurve.cc
+++ b/rtgui/tonecurve.cc
@@ -953,7 +953,6 @@ bool ToneCurve::histmatchingComputed()
         autolevels->set_inconsistent(false);
     }
 
-    histmatching->set_active(false);
     toneCurveMode->set_active(rtengine::toUnderlying(nextToneCurveMode));
     shape->setCurve(nextToneCurve);
     shape2->setCurve({ DCT_Linear });