diff --git a/rtengine/color.h b/rtengine/color.h
index 1eb799cda..cc3a1f295 100644
--- a/rtengine/color.h
+++ b/rtengine/color.h
@@ -954,7 +954,7 @@ public:
     */
     static inline double gamma13_2     (double x)
     {
-        return x <= 0.016613 ? x * 2.0 : 1.009968 * exp(log(x) / 1.3) - 0.016613;
+        return x <= 0.016613 ? x * 2.0 : 1.009968 * exp(log(x) / 1.3) - 0.009968;
     }
     
     static inline double igamma13_2    (double x)
@@ -964,7 +964,7 @@ public:
 
     static inline double gamma115_2     (double x)
     {
-        return x <= 0.001692 ? x * 2.0 : 1.000508 * exp(log(x) / 1.15) - 0.001692;
+        return x <= 0.001692 ? x * 2.0 : 1.000508 * exp(log(x) / 1.15) - 0.000508;
     }
     
     static inline double igamma115_2    (double x)
@@ -974,7 +974,7 @@ public:
     
     static inline double gamma145_3     (double x)
     {
-        return x <= 0.009115 ? x * 3.0 : 1.012305 * exp(log(x) / 1.45) - 0.009115;
+        return x <= 0.009115 ? x * 3.0 : 1.012305 * exp(log(x) / 1.45) - 0.012305;
     }
     
     static inline double igamma145_3    (double x)
diff --git a/rtengine/rawimagesource.cc b/rtengine/rawimagesource.cc
index 3b4eecaf4..ae52227f5 100644
--- a/rtengine/rawimagesource.cc
+++ b/rtengine/rawimagesource.cc
@@ -1834,7 +1834,7 @@ void RawImageSource::retinexPrepareBuffers(ColorManagementParams cmp, RetinexPar
             for (int i = 0; i < 65536; i++) {
                 double val = (i) / 65535.;
                 double start = g_a3;
-                double add = g_a3;
+                double add = g_a4;
                 double mul = 1. + g_a4;
                 double x;
                 x = Color::gammareti (val, gamm, start, ts, mul , add);