diff --git a/src/app/commands/cmd_zoom.cpp b/src/app/commands/cmd_zoom.cpp
index 9ef7db102..f0e1f1edb 100644
--- a/src/app/commands/cmd_zoom.cpp
+++ b/src/app/commands/cmd_zoom.cpp
@@ -33,13 +33,14 @@ protected:
 
 private:
   Action m_action;
-  int m_percentage;
+  render::Zoom m_zoom;
 };
 
 ZoomCommand::ZoomCommand()
   : Command("Zoom",
             "Zoom",
             CmdUIOnlyFlag)
+  , m_zoom(1, 1)
 {
 }
 
@@ -52,7 +53,8 @@ void ZoomCommand::onLoadParams(const Params& params)
 
   std::string percentage = params.get("percentage");
   if (!percentage.empty()) {
-    m_percentage = std::strtol(percentage.c_str(), NULL, 10);
+    m_zoom = render::Zoom::fromScale(
+      std::strtod(percentage.c_str(), NULL) / 100.0);
     m_action = Set;
   }
 }
@@ -74,7 +76,7 @@ void ZoomCommand::onExecute(Context* context)
       zoom.out();
       break;
     case Set:
-      zoom = render::Zoom::fromScale(double(m_percentage) / 100.0);
+      zoom = m_zoom;
       break;
   }
 
@@ -93,7 +95,7 @@ std::string ZoomCommand::onGetFriendlyName() const
       text += " out";
       break;
     case Set:
-      text += " " + base::convert_to<std::string>(m_percentage) + "%";
+      text += " " + base::convert_to<std::string>(int(100.0*m_zoom.scale())) + "%";
       break;
   }
 
diff --git a/src/app/file/gif_format.cpp b/src/app/file/gif_format.cpp
index bff053862..6dfd477b4 100644
--- a/src/app/file/gif_format.cpp
+++ b/src/app/file/gif_format.cpp
@@ -535,7 +535,7 @@ bool GifFormat::onSave(FileOp* fop)
   PixelFormat sprite_format = sprite->pixelFormat();
   bool interlaced = gif_options->interlaced();
   int loop = (gif_options->loop() ? 0: -1);
-  bool has_background = (sprite->backgroundLayer() ? true: false);
+  bool has_background = (sprite->backgroundLayer() && sprite->backgroundLayer()->isVisible());
   int background_color = (sprite_format == IMAGE_INDEXED ? sprite->transparentColor(): 0);
   int transparent_index = (has_background ? -1: sprite->transparentColor());
 
diff --git a/src/app/file/png_format.cpp b/src/app/file/png_format.cpp
index e169057cd..5ebf325b6 100644
--- a/src/app/file/png_format.cpp
+++ b/src/app/file/png_format.cpp
@@ -414,10 +414,11 @@ bool PngFormat::onSave(FileOp* fop)
 
     png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH);
 
-    // If the sprite does not have a background layer, we include the
-    // alpha information of palette entries to indicate which is the
-    // transparent color.
-    if (fop->document->sprite()->backgroundLayer() == NULL) {
+    // If the sprite does not have a (visible) background layer, we
+    // include the alpha information of palette entries to indicate
+    // which is the transparent color.
+    if (fop->document->sprite()->backgroundLayer() == NULL ||
+        !fop->document->sprite()->backgroundLayer()->isVisible()) {
       int mask_entry = fop->document->sprite()->transparentColor();
       int num_trans = mask_entry+1;
       png_bytep trans = (png_bytep)png_malloc(png_ptr, num_trans);
diff --git a/src/doc/sprite.cpp b/src/doc/sprite.cpp
index ce3333946..58f98b5c9 100644
--- a/src/doc/sprite.cpp
+++ b/src/doc/sprite.cpp
@@ -150,8 +150,10 @@ bool Sprite::needAlpha() const
 {
   switch (m_format) {
     case IMAGE_RGB:
-    case IMAGE_GRAYSCALE:
-      return (backgroundLayer() == NULL);
+    case IMAGE_GRAYSCALE: {
+      Layer* bg = backgroundLayer();
+      return (!bg || !bg->isVisible());
+    }
   }
   return false;
 }