diff --git a/tutorial-contents/402_RNN_classifier.py b/tutorial-contents/402_RNN_classifier.py
index 679a255..1909387 100644
--- a/tutorial-contents/402_RNN_classifier.py
+++ b/tutorial-contents/402_RNN_classifier.py
@@ -56,7 +56,7 @@ class RNN(nn.Module):
         super(RNN, self).__init__()
 
         self.rnn = nn.LSTM(         # if use nn.RNN(), it hardly learns
-            input_size=28,
+            input_size=INPUT_SIZE,
             hidden_size=64,         # rnn hidden unit
             num_layers=1,           # number of rnn layer
             batch_first=True,       # input & output will has batch size as 1s dimension. e.g. (batch, time_step, input_size)