diff --git a/generator b/generator
index c99abea..f958817 100755
--- a/generator
+++ b/generator
@@ -25,7 +25,7 @@ from click import progressbar
 import glob, os, random, shutil, math, tempfile
 
 
-TMP_FRAMES_PATH = tempfile.mkstemp()[1]
+TMP_FRAMES_PATH = tempfile.mkdtemp()
 
 def generate_video_thumbnail(args):
     videoFileClip = VideoFileClip(args['<video>'])
@@ -63,9 +63,14 @@ def generate_sprite_from_frames(framesPath, columns, size, output):
     masterWidth = size[0] * columns
     masterHeight = size[1] * int(math.ceil(float(len(framesMap)) / columns))
 
-    line, column = 0, 0
+    line, column, mode = 0, 0, 'RGBA'
 
-    finalImage = Image.new(mode='RGBA', size=(masterWidth, masterHeight), color=(0,0,0,0))
+    try:
+        finalImage = Image.new(mode=mode, size=(masterWidth, masterHeight), color=(0,0,0,0))
+        finalImage.save(output)
+    except IOError:
+        mode = 'RGB'
+        finalImage = Image.new(mode=mode, size=(masterWidth, masterHeight))
 
     for filename in framesMap:
         with Image.open(filename) as image:              
@@ -81,14 +86,14 @@ def generate_sprite_from_frames(framesPath, columns, size, output):
                 line += 1
                 column = 0
 
-    finalImage.save(output, transparency=0)
+    finalImage.save(output)
     shutil.rmtree(TMP_FRAMES_PATH, ignore_errors=True)
     print "Saved!"
 
 def get_output_prefix():
     if not os.path.exists(TMP_FRAMES_PATH):
         os.makedirs(TMP_FRAMES_PATH)
-    return TMP_FRAMES_PATH + ("%032x_" % random.getrandbits(128))
+    return TMP_FRAMES_PATH + os.sep + ("%032x_" % random.getrandbits(128))
 
 if __name__ == "__main__":
     arguments = docopt(__doc__, version='0.0.2')