diff --git a/rtengine/dcrop.cc b/rtengine/dcrop.cc
index 818d4d8bb..8bcd1e6a3 100644
--- a/rtengine/dcrop.cc
+++ b/rtengine/dcrop.cc
@@ -715,6 +715,13 @@ void Crop::update (int todo)
         transCrop = nullptr;
     }
 
+    std::unique_ptr<Imagefloat> fattalCrop;
+    if ((todo & M_RGBCURVE) && params.fattal.enabled) {
+        fattalCrop.reset(baseCrop->copy());
+        parent->ipf.ToneMapFattal02(fattalCrop.get());
+        baseCrop = fattalCrop.get();
+    }
+    
     if ((todo & (M_TRANSFORM | M_RGBCURVE))  && params.dirpyrequalizer.cbdlMethod == "bef" && params.dirpyrequalizer.enabled && !params.colorappearance.enabled) {
 
         const int W = baseCrop->getWidth();
@@ -808,10 +815,6 @@ void Crop::update (int todo)
         parent->ipf.chromiLuminanceCurve (this, 1, labnCrop, labnCrop, parent->chroma_acurve, parent->chroma_bcurve, parent->satcurve, parent->lhskcurve,  parent->clcurve, parent->lumacurve, utili, autili, butili, ccutili, cclutili, clcutili, dummy, dummy);
         parent->ipf.vibrance (labnCrop);
 
-        if (params.fattal.enabled) {
-            parent->ipf.ToneMapFattal02(labnCrop, 3);
-        }
-        
         if ((params.colorappearance.enabled && !params.colorappearance.tonecie) ||  (!params.colorappearance.enabled)) {
             parent->ipf.EPDToneMap (labnCrop, 5, skip);
         }
diff --git a/rtengine/improccoordinator.cc b/rtengine/improccoordinator.cc
index e3ff874b6..dffd9572e 100644
--- a/rtengine/improccoordinator.cc
+++ b/rtengine/improccoordinator.cc
@@ -407,6 +407,15 @@ void ImProcCoordinator::updatePreviewImage (int todo, Crop* cropCall)
         }
     }
 
+    if ((todo & M_RGBCURVE) && params.fattal.enabled) {
+        Imagefloat *fattalprev = oprevi->copy();
+        ipf.ToneMapFattal02(fattalprev);
+        if (oprevi != orig_prev) {
+            delete oprevi;
+        }
+        oprevi = fattalprev;
+    } 
+
     if ((todo & (M_TRANSFORM | M_RGBCURVE))  && params.dirpyrequalizer.cbdlMethod == "bef" && params.dirpyrequalizer.enabled && !params.colorappearance.enabled) {
         const int W = oprevi->getWidth();
         const int H = oprevi->getHeight();
@@ -636,10 +645,6 @@ void ImProcCoordinator::updatePreviewImage (int todo, Crop* cropCall)
         ipf.chromiLuminanceCurve (nullptr, pW, nprevl, nprevl, chroma_acurve, chroma_bcurve, satcurve, lhskcurve, clcurve, lumacurve, utili, autili, butili, ccutili, cclutili, clcutili, histCCurve, histLCurve);
         ipf.vibrance (nprevl);
 
-        if (params.fattal.enabled) {
-            ipf.ToneMapFattal02(nprevl, 3);
-        }
-        
         if ((params.colorappearance.enabled && !params.colorappearance.tonecie) ||  (!params.colorappearance.enabled)) {
             ipf.EPDToneMap (nprevl, 5, scale);
         }
diff --git a/rtengine/improcfun.h b/rtengine/improcfun.h
index c1e4a1e35..46ad670fa 100644
--- a/rtengine/improcfun.h
+++ b/rtengine/improcfun.h
@@ -347,7 +347,7 @@ public:
     void Badpixelscam (CieImage * src, CieImage * dst, double radius, int thresh, int mode,  float b_l, float t_l, float t_r, float b_r, float skinprot, float chrom, int hotbad);
     void BadpixelsLab (LabImage * src, LabImage * dst, double radius, int thresh, int mode, float b_l, float t_l, float t_r, float b_r, float skinprot, float chrom);
 
-    void ToneMapFattal02(LabImage *lab, int detail_level);
+    void ToneMapFattal02(Imagefloat *rgb);
     
     Image8*     lab2rgb   (LabImage* lab, int cx, int cy, int cw, int ch, const procparams::ColorManagementParams &icm);
     Image16*    lab2rgb16 (LabImage* lab, int cx, int cy, int cw, int ch, const procparams::ColorManagementParams &icm, bool bw, GammaValues *ga = nullptr);
diff --git a/rtengine/rtthumbnail.cc b/rtengine/rtthumbnail.cc
index 6cc50a6a8..efe5d7868 100644
--- a/rtengine/rtthumbnail.cc
+++ b/rtengine/rtthumbnail.cc
@@ -1102,6 +1102,10 @@ IImage8* Thumbnail::processImage (const procparams::ProcParams& params, eSensorT
         baseImg = trImg;
     }
 
+    if (params.fattal.enabled) {
+        ipf.ToneMapFattal02(baseImg);
+    }
+
     // update blurmap
     SHMap* shmap = nullptr;
 
@@ -1275,10 +1279,6 @@ IImage8* Thumbnail::processImage (const procparams::ProcParams& params, eSensorT
 
     ipf.vibrance (labView);
 
-    if (params.fattal.enabled) {
-        ipf.ToneMapFattal02(labView, 0);
-    }
-
     if ((params.colorappearance.enabled && !params.colorappearance.tonecie) || !params.colorappearance.enabled) {
         ipf.EPDToneMap (labView, 5, 6);
     }
diff --git a/rtengine/simpleprocess.cc b/rtengine/simpleprocess.cc
index de57386dd..c8d45acf8 100644
--- a/rtengine/simpleprocess.cc
+++ b/rtengine/simpleprocess.cc
@@ -833,6 +833,10 @@ private:
         //ImProcFunctions ipf (&params, true);
         ImProcFunctions &ipf = * (ipf_p.get());
 
+        if (params.fattal.enabled) {
+            ipf.ToneMapFattal02(baseImg);
+        }
+        
         if (params.dirpyrequalizer.cbdlMethod == "bef" && params.dirpyrequalizer.enabled && !params.colorappearance.enabled) {
             const int W = baseImg->getWidth();
             const int H = baseImg->getHeight();
@@ -1013,10 +1017,6 @@ private:
 
         ipf.chromiLuminanceCurve (nullptr, 1, labView, labView, curve1, curve2, satcurve, lhskcurve, clcurve, lumacurve, utili, autili, butili, ccutili, cclutili, clcutili, dummy, dummy);
 
-        if (params.fattal.enabled) {
-            ipf.ToneMapFattal02(labView, 3);
-        }
-
         if ((params.colorappearance.enabled && !params.colorappearance.tonecie) || (!params.colorappearance.enabled)) {
             ipf.EPDToneMap (labView, 5, 1);
         }
diff --git a/rtengine/tmo_fattal02.cc b/rtengine/tmo_fattal02.cc
index 9d015dfdb..768a296b2 100644
--- a/rtengine/tmo_fattal02.cc
+++ b/rtengine/tmo_fattal02.cc
@@ -1030,7 +1030,9 @@ void rescale_bilinear(const Array2Df &src, Array2Df &dst, bool multithread)
     float col_scale = float(src.getCols())/float(dst.getCols());
     float row_scale = float(src.getRows())/float(dst.getRows());
 
+#ifdef _OPENMP
     #pragma omp parallel for if (multithread)
+#endif
     for (int x = 0; x < dst.getCols(); ++x) {
         for (int y = 0; y < dst.getRows(); ++y) {
             dst(x, y) = get_bilinear_value(src, x * col_scale, y * row_scale);
@@ -1047,17 +1049,17 @@ void tmo_fattal02_RT(Imagefloat *rgb, float alpha, float beta, int detail_level,
     Array2Df Yr(w, h);
     Array2Df L(w, h);
 
-    rgb->normalizeFloatTo1();
-
+    const float epsilon = 1e-4f;
+    
+#ifdef _OPENMP
     #pragma omp parallel for if (multiThread)
+#endif
     for (int y = 0; y < h; y++) {
         for (int x = 0; x < w; x++) {
-            Yr(x, y) = Color::rgbLuminance(rgb->r(y, x), rgb->g(y, x), rgb->b(y, x));
+            Yr(x, y) = std::max(Color::rgbLuminance(rgb->r(y, x), rgb->g(y, x), rgb->b(y, x)), epsilon); // clip really black pixels, otherwise it doesn't work at all (not sure why...)
         }
     }
 
-    // float alpha = params->fattal.alpha;
-    // float beta = params->fattal.beta;
     float noise = alpha * 0.01f;
 
     if (settings->verbose) {
@@ -1067,10 +1069,9 @@ void tmo_fattal02_RT(Imagefloat *rgb, float alpha, float beta, int detail_level,
 
     tmo_fattal02(w, h, Yr, L, alpha, beta, noise, detail_level, multiThread);
 
-    const float epsilon = 1e-4f;
     for (int y = 0; y < h; y++) {
         for (int x = 0; x < w; x++) {
-            float Y = std::max(Yr(x, y), epsilon);
+            float Y = Yr(x, y);
             float l = std::max(L(x, y), epsilon);
             rgb->r(y, x) = std::max(rgb->r(y, x)/Y, 0.f) * l;
             rgb->g(y, x) = std::max(rgb->g(y, x)/Y, 0.f) * l;
@@ -1084,12 +1085,11 @@ void tmo_fattal02_RT(Imagefloat *rgb, float alpha, float beta, int detail_level,
 } // namespace
 
 
-void ImProcFunctions::ToneMapFattal02(LabImage *lab, int detail_level)
+void ImProcFunctions::ToneMapFattal02(Imagefloat *rgb)
 {
-    Imagefloat tmp(lab->W, lab->H);
-    lab2rgb(*lab, tmp, params->icm.working);
-    tmo_fattal02_RT(&tmp, params->fattal.alpha, params->fattal.beta, detail_level, multiThread);
-    rgb2lab(tmp, *lab, params->icm.working);
+    const int detail_level = 3;
+    tmo_fattal02_RT(rgb, params->fattal.alpha, params->fattal.beta, detail_level, multiThread);
 }
 
+
 } // namespace rtengine