diff --git a/mtdUtils.py b/mtdUtils.py
index 2c1303d229cb3ed384596d0ff82eedf9ee887cd4..99739067b1a1ec96f717092b58d6bf57d29db4ae 100644
--- a/mtdUtils.py
+++ b/mtdUtils.py
@@ -562,7 +562,7 @@ def randomword(length):
 
     OUTPUT	:	random word (string)
     """
-    return ''.join(random.choice(string.lowercase) for i in range(length))
+    return ''.join(random.choice(string.ascii_lowercase) for i in range(length))
 
 
 def rescaleImage(img, outmin=0, outmax=255, nodata=None, bw=False):
diff --git a/prepareS2THEIA.py b/prepareS2THEIA.py
index 77764f3ad66542423fb14373ed27ff5317691853..84c587f41feebf9e106b2f10fd8204ba1c9be9d0 100644
--- a/prepareS2THEIA.py
+++ b/prepareS2THEIA.py
@@ -26,7 +26,7 @@ def genScript(argv):
     clipping = False
     clip_shp = None
     single_tile = ''
-
+    srs = None
     for opt, val in opts:
         if opt == '-o':
             od = val
@@ -38,7 +38,7 @@ def genScript(argv):
         elif opt == '--srs':
             srs = str(val)
     if srs is None :
-        ds = gdal.Open(glob.glob(dirs[0] + '/GRANULE/*/IMG_DATA/*_B2.tif')[0])
+        ds = gdal.Open(glob.glob(dirs[0] + '/*_B2.tif')[0])
         prj = ds.GetProjectionRef()
         srs = osr.SpatialReference(prj)
         srs = 'EPSG:'+srs.GetAuthorityCode('PROJCS')
@@ -56,11 +56,11 @@ def genScript(argv):
             mtd = glob.glob(dir + '/*_MTD_ALL.xml')
             if len(mtd) > 0:
                 #cmd = ['python', 'prepareS2THEIA.py'] + argv[:-1] + [dir]
-                cmd = ['python', 'prepareS2THEIA.py', '-o', '\"' + od + '\"']
+                cmd = ['python', 'prepareS2THEIA.py', '-o', od]
                 if clip_shp is not None:
-                    cmd += ['-c', '\"' + clip_shp + '\"']
+                    cmd += ['-c', clip_shp]
                 cmd += ['--srs', srs]
-                cmd += ['\"' + dir + '\"']
+                cmd += [dir]
                 f.write(' '.join(cmd) + '\n')
     f.close()