before_install_linux.sh in rmagick-2.15.3 vs before_install_linux.sh in rmagick-2.15.4

@@ -3,16 +3,16 @@
 sudo apt-get remove -y imagemagick
 sudo apt-get install -y build-essential libx11-dev libxext-dev zlib1g-dev libpng12-dev libjpeg-dev libfreetype6-dev libxml2-dev
 sudo apt-get build-dep -y imagemagick
 case $IMAGEMAGICK_VERSION in
     latest)
-        wget http://www.imagemagick.org/download/ImageMagick.tar.gz
-        tar -xzvf ImageMagick.tar.gz
+        wget http://www.imagemagick.org/download/ImageMagick.tar.xz
+        tar -xf ImageMagick.tar.xz
         cd ImageMagick-*
     ;;
     *)
-        wget http://www.imagemagick.org/download/releases/ImageMagick-${IMAGEMAGICK_VERSION}.tar.gz
-        tar -xzvf ImageMagick-${IMAGEMAGICK_VERSION}.tar.gz
+        wget http://www.imagemagick.org/download/releases/ImageMagick-${IMAGEMAGICK_VERSION}.tar.xz
+        tar -xf ImageMagick-${IMAGEMAGICK_VERSION}.tar.xz
         cd ImageMagick-${IMAGEMAGICK_VERSION}
     ;;
 esac
 ./configure --prefix=/usr $CONFIGURE_OPTIONS
 sudo make install