diff --git a/poppler/SplashOutputDev.cc b/poppler/SplashOutputDev.cc
index 5f84f2c..2287d32 100644
--- a/poppler/SplashOutputDev.cc
+++ b/poppler/SplashOutputDev.cc
@@ -3987,6 +3987,11 @@ void SplashOutputDev::setSoftMask(GfxState *state, double *bbox,
   for (y = 0; y < yMax; ++y) {
     for (x = 0; x < xMax; ++x) {
       if (alpha) {
+        if (transferFunc) {
+          lum = tBitmap->getAlpha(x, y) / 255.0;
+	        transferFunc->transform(&lum, &lum2);
+	        p[x] = (int)(lum2 * 255.0 + 0.5);
+        } else 
 	p[x] = tBitmap->getAlpha(x, y);
       } else {
 	  tBitmap->getPixel(x, y, color);