diff --git a/tf2onnx/tf_loader.py b/tf2onnx/tf_loader.py
index 2f969f77e..2a30eeae2 100644
--- a/tf2onnx/tf_loader.py
+++ b/tf2onnx/tf_loader.py
@@ -290,8 +290,8 @@ def from_function(func, input_names, output_names, large_model=False):
 
 def freeze_session(sess, input_names=None, output_names=None, get_tables=False):
     """Freezes the state of a session into a pruned computation graph."""
-    output_node_names = [i.split(':')[:-1][0] for i in output_names]
-    keep_var_names = [i.split(':')[:-1][0] for i in input_names]
+    output_node_names = [i.split(':')[0] for i in output_names]
+    keep_var_names = [i.split(':')[0] for i in input_names]
     with sess.graph.as_default():
         output_node_names = output_node_names or []
         output_node_names += [v.op.name for v in tf_global_variables()]