diff --git a/cgat/AString.py b/cgat/AString.py
index 6fa95a68..cfb8441d 100644
--- a/cgat/AString.py
+++ b/cgat/AString.py
@@ -55,7 +55,7 @@ def __getitem__(self, *args):
         """return slice as a string."""
 
         if IS_PY3:
-            return array.__getitem__(self, *args).tostring().decode("ascii")
+            return array.__getitem__(self, *args).tobytes().decode("ascii")
         else:
             return array.__getitem__(self, *args).tostring()
 
@@ -67,6 +67,6 @@ def __setitem__(self, start, end, sub):
 
     def __str__(self):
         if IS_PY3:
-            return self.tostring().decode("ascii")
+            return self.tobytes().decode("ascii")
         else:
             return self.tostring()
diff --git a/cgat/tools/gtf2fasta.py b/cgat/tools/gtf2fasta.py
index 545682d4..bb746414 100644
--- a/cgat/tools/gtf2fasta.py
+++ b/cgat/tools/gtf2fasta.py
@@ -470,7 +470,6 @@ def annotateGenome(iterator, fasta, options, default_code=DEFAULT_CODE):
 
     E.info("started output")
     for k in sorted(annotations.keys()):
-        # options.stdout.write(">%s\n%s\n" % (k, annotations[k].tostring()))
         options.stdout.write(">%s\n%s\n" % (k, "".join(annotations[k])))