diff --git a/autotests/read/psd/birthday.png b/autotests/read/psd/birthday.png
deleted file mode 100644
index a79391f..0000000
Binary files a/autotests/read/psd/birthday.png and /dev/null differ
diff --git a/autotests/read/psd/birthday.tif b/autotests/read/psd/birthday.tif
new file mode 100644
index 0000000..7e0d5f0
Binary files /dev/null and b/autotests/read/psd/birthday.tif differ
diff --git a/autotests/readtest.cpp b/autotests/readtest.cpp
index bf0fb07..7710844 100644
--- a/autotests/readtest.cpp
+++ b/autotests/readtest.cpp
@@ -159,17 +159,22 @@ int main(int argc, char **argv)
             QTextStream(stdout) << "* Run on RANDOM ACCESS device\n";
         }
         for (const QFileInfo &fi : lstImgDir) {
-            if (!fi.suffix().compare("png", Qt::CaseInsensitive)) {
+            if (!fi.suffix().compare("png", Qt::CaseInsensitive) || !fi.suffix().compare("tif", Qt::CaseInsensitive)) {
                 continue;
             }
             int suffixPos = fi.filePath().count() - suffix.count();
             QString inputfile = fi.filePath();
-            QString expfile = fi.filePath().replace(suffixPos, suffix.count(), QStringLiteral("png"));
+            QString fmt = QStringLiteral("png");
+            QString expfile = fi.filePath().replace(suffixPos, suffix.count(), fmt);
+            if (!QFile::exists(expfile)) { // try with tiff
+                fmt = QStringLiteral("tif");
+                expfile = fi.filePath().replace(suffixPos, suffix.count(), fmt);
+            }
             QString expfilename = QFileInfo(expfile).fileName();
 
             std::unique_ptr<QIODevice> inputDevice(seq ? new SequentialFile(inputfile) : new QFile(inputfile));
             QImageReader inputReader(inputDevice.get(), format);
-            QImageReader expReader(expfile, "png");
+            QImageReader expReader(expfile, fmt.toLatin1());
 
             QImage inputImage;
             QImage expImage;
diff --git a/src/imageformats/psd.cpp b/src/imageformats/psd.cpp
index 3ea66d7..be01159 100644
--- a/src/imageformats/psd.cpp
+++ b/src/imageformats/psd.cpp
@@ -847,8 +847,7 @@ inline void premulConversion(char *stride, qint32 width, qint32 ac, qint32 cn, c
             for (qint32 x = 0; x < width; ++x) {
                 auto xcn = x * cn;
                 auto alpha = *(s + xcn + ac);
-                if (alpha > 0)
-                    *(s + xcn + c) = *(s + xcn + c) + alpha - max;
+                *(s + xcn + c) = *(s + xcn + c) + alpha - max;
             }
         } else if (conv == PremulConversion::PS2A || (conv == PremulConversion::PSLab2A && c == 0)) {
             for (qint32 x = 0; x < width; ++x) {