diff --git a/ethosu/vela/tflite_reader.py b/ethosu/vela/tflite_reader.py
index 84c4c3c..5667aff 100644
--- a/ethosu/vela/tflite_reader.py
+++ b/ethosu/vela/tflite_reader.py
@@ -20,7 +20,6 @@
 import numpy as np
 
 from .errors import InputFileError
-from .errors import UnsupportedFeatureError
 from .nn_graph import Graph
 from .nn_graph import Subgraph
 from .operation import Operation
@@ -229,7 +228,7 @@
 
     def parse_operator_code(self, code):
         c = code.BuiltinCode()
-        if not c in builtin_operator_map:
+        if c not in builtin_operator_map:
             msg = "The input file contains operator code {} which is currently not supported".format(c)
             raise InputFileError(self.name, msg)
         op_type, ser = builtin_operator_map[c]