diff --git a/poppler/SplashOutputDev.cc b/poppler/SplashOutputDev.cc
index ab0722a..eb45b16 100644
--- a/poppler/SplashOutputDev.cc
+++ b/poppler/SplashOutputDev.cc
@@ -2901,7 +2901,6 @@ void SplashOutputDev::beginTransparencyGroup(GfxState *state, double *bbox,
   state->shiftCTM(-tx, -ty);
   updateCTM(state, 0, 0, 0, 0, 0, 0);
 }
-
 void SplashOutputDev::endTransparencyGroup(GfxState *state) {
   double *ctm;
 
@@ -2937,9 +2936,9 @@ void SplashOutputDev::paintTransparencyGroup(GfxState * /*state*/, double * /*bb
   delete transpGroup;
 
   delete tBitmap;
-}
+ }
 
-void SplashOutputDev::setSoftMask(GfxState * /*state*/, double * /*bbox*/,
+void SplashOutputDev::setSoftMask(GfxState * state, double * /*bbox*/,
 				  GBool alpha, Function *transferFunc,
 				  GfxColor *backdropColor) {
   SplashBitmap *softMask, *tBitmap;
@@ -3002,7 +3001,8 @@ void SplashOutputDev::setSoftMask(GfxState * /*state*/, double * /*bbox*/,
 
   softMask = new SplashBitmap(bitmap->getWidth(), bitmap->getHeight(),
 			      1, splashModeMono8, gFalse);
-  memset(softMask->getDataPtr(), 0,
+  unsigned char fill = (state->getAlphaIsShape()) ? 255 : 0;
+  memset(softMask->getDataPtr(), fill,
 	 softMask->getRowSize() * softMask->getHeight());
   p = softMask->getDataPtr() + ty * softMask->getRowSize() + tx;
   int xMax = tBitmap->getWidth();