diff --git a/keras/layers/rnn/lstm.py b/keras/layers/rnn/lstm.py
index 73ed18aac8d..761d222d6dd 100644
--- a/keras/layers/rnn/lstm.py
+++ b/keras/layers/rnn/lstm.py
@@ -233,9 +233,9 @@ def call(self, inputs, states, training=False):
         rec_dp_mask = self.get_recurrent_dropout_mask(h_tm1)
 
         if training and 0.0 < self.dropout < 1.0:
-            inputs *= dp_mask
+            inputs = inputs * dp_mask
         if training and 0.0 < self.recurrent_dropout < 1.0:
-            h_tm1 *= rec_dp_mask
+            h_tm1 = h_tm1 * rec_dp_mask
 
         if self.implementation == 1:
             inputs_i = inputs