diff --git a/rtengine/capturesharpening.cc b/rtengine/capturesharpening.cc
index d2bb6b351..e5bfde555 100644
--- a/rtengine/capturesharpening.cc
+++ b/rtengine/capturesharpening.cc
@@ -800,7 +800,7 @@ BENCHFUN
         }
 
         array2D<float>& blend = red; // red will be overridden anyway => we can use its buffer to store the blend mask
-        buildBlendMask(L, blend, W, H, contrast, 1.f, sharpeningParams.autoContrast, clipMask);
+        buildBlendMask(L, blend, W, H, contrast, sharpeningParams.autoContrast, clipMask);
         if (plistener) {
             plistener->setProgress(0.2);
         }
@@ -849,7 +849,7 @@ BENCHFUN
     }
     // calculate contrast based blend factors to reduce sharpening in regions with low contrast
     array2D<float>& blend = clipMask; // we can share blend and clipMask buffer here
-    buildBlendMask(L, blend, W, H, contrast, 1.f, sharpeningParams.autoContrast, clipMask);
+    buildBlendMask(L, blend, W, H, contrast, sharpeningParams.autoContrast, clipMask);
     if (plistener) {
         plistener->setProgress(0.2);
     }
diff --git a/rtengine/dual_demosaic_RT.cc b/rtengine/dual_demosaic_RT.cc
index 69d1a189a..93508808c 100644
--- a/rtengine/dual_demosaic_RT.cc
+++ b/rtengine/dual_demosaic_RT.cc
@@ -105,7 +105,7 @@ void RawImageSource::dual_demosaic_RT(bool isBayer, const procparams::RAWParams
     JaggedArray<float> blend(winw, winh);
     float contrastf = contrast / 100.f;
 
-    buildBlendMask(L, blend, winw, winh, contrastf, 1.f, autoContrast);
+    buildBlendMask(L, blend, winw, winh, contrastf, autoContrast);
     contrast = contrastf * 100.f;
 
     array2D<float>& redTmp = L; // L is not needed anymore => reuse it
diff --git a/rtengine/ipsharpen.cc b/rtengine/ipsharpen.cc
index a35476d3a..7198b76c5 100644
--- a/rtengine/ipsharpen.cc
+++ b/rtengine/ipsharpen.cc
@@ -256,7 +256,7 @@ void ImProcFunctions::sharpening (LabImage* lab, const procparams::SharpeningPar
     // calculate contrast based blend factors to reduce sharpening in regions with low contrast
     JaggedArray<float> blend(W, H);
     float contrast = sharpenParam.contrast / 100.f;
-    buildBlendMask(lab->L, blend, W, H, contrast, 1.f);
+    buildBlendMask(lab->L, blend, W, H, contrast);
 
     if(showMask) {
 #ifdef _OPENMP
diff --git a/rtengine/rt_algo.cc b/rtengine/rt_algo.cc
index 79a7c3679..a5b48af95 100644
--- a/rtengine/rt_algo.cc
+++ b/rtengine/rt_algo.cc
@@ -299,7 +299,7 @@ void findMinMaxPercentile(const float* data, size_t size, float minPrct, float&
     maxOut = rtengine::LIM(maxOut, minVal, maxVal);
 }
 
-void buildBlendMask(const float* const * luminance, float **blend, int W, int H, float &contrastThreshold, float amount, bool autoContrast, float ** clipMask) {
+void buildBlendMask(const float* const * luminance, float **blend, int W, int H, float &contrastThreshold, bool autoContrast, float ** clipMask) {
 
     if (autoContrast) {
         constexpr float minLuminance = 2000.f;
@@ -403,7 +403,7 @@ void buildBlendMask(const float* const * luminance, float **blend, int W, int H,
     if(contrastThreshold == 0.f) {
         for(int j = 0; j < H; ++j) {
             for(int i = 0; i < W; ++i) {
-                blend[j][i] = amount;
+                blend[j][i] = 1.f;
             }
         }
     } else {
@@ -415,7 +415,6 @@ void buildBlendMask(const float* const * luminance, float **blend, int W, int H,
 #ifdef __SSE2__
             const vfloat contrastThresholdv = F2V(contrastThreshold);
             const vfloat scalev = F2V(scale);
-            const vfloat amountv = F2V(amount);
 #endif
 #ifdef _OPENMP
             #pragma omp for schedule(dynamic,16)
@@ -429,14 +428,14 @@ void buildBlendMask(const float* const * luminance, float **blend, int W, int H,
                         vfloat contrastv = vsqrtf(SQRV(LVFU(luminance[j][i+1]) - LVFU(luminance[j][i-1])) + SQRV(LVFU(luminance[j+1][i]) - LVFU(luminance[j-1][i])) +
                                                   SQRV(LVFU(luminance[j][i+2]) - LVFU(luminance[j][i-2])) + SQRV(LVFU(luminance[j+2][i]) - LVFU(luminance[j-2][i]))) * scalev;
 
-                        STVFU(blend[j][i], LVFU(clipMask[j][i]) * amountv * calcBlendFactor(contrastv, contrastThresholdv));
+                        STVFU(blend[j][i], LVFU(clipMask[j][i]) * calcBlendFactor(contrastv, contrastThresholdv));
                     }
                 } else {
                     for(; i < W - 5; i += 4) {
                         vfloat contrastv = vsqrtf(SQRV(LVFU(luminance[j][i+1]) - LVFU(luminance[j][i-1])) + SQRV(LVFU(luminance[j+1][i]) - LVFU(luminance[j-1][i])) +
                                                   SQRV(LVFU(luminance[j][i+2]) - LVFU(luminance[j][i-2])) + SQRV(LVFU(luminance[j+2][i]) - LVFU(luminance[j-2][i]))) * scalev;
 
-                        STVFU(blend[j][i], amountv * calcBlendFactor(contrastv, contrastThresholdv));
+                        STVFU(blend[j][i], calcBlendFactor(contrastv, contrastThresholdv));
                     }
                 }
 #endif
@@ -445,7 +444,7 @@ void buildBlendMask(const float* const * luminance, float **blend, int W, int H,
                     float contrast = sqrtf(rtengine::SQR(luminance[j][i+1] - luminance[j][i-1]) + rtengine::SQR(luminance[j+1][i] - luminance[j-1][i]) + 
                                            rtengine::SQR(luminance[j][i+2] - luminance[j][i-2]) + rtengine::SQR(luminance[j+2][i] - luminance[j-2][i])) * scale;
 
-                    blend[j][i] = (clipMask ? clipMask[j][i] : 1.f) * amount * calcBlendFactor(contrast, contrastThreshold);
+                    blend[j][i] = (clipMask ? clipMask[j][i] : 1.f) * calcBlendFactor(contrast, contrastThreshold);
                 }
             }
 
diff --git a/rtengine/rt_algo.h b/rtengine/rt_algo.h
index 5485346c7..81147fd75 100644
--- a/rtengine/rt_algo.h
+++ b/rtengine/rt_algo.h
@@ -24,5 +24,5 @@
 namespace rtengine
 {
 void findMinMaxPercentile(const float* data, size_t size, float minPrct, float& minOut, float maxPrct, float& maxOut, bool multiThread = true);
-void buildBlendMask(const float* const * luminance, float **blend, int W, int H, float &contrastThreshold, float amount = 1.f, bool autoContrast = false, float ** clipmask = nullptr);
+void buildBlendMask(const float* const * luminance, float **blend, int W, int H, float &contrastThreshold, bool autoContrast = false, float ** clipmask = nullptr);
 }