diff --git a/neuralnetworks/1.3/types.hal b/neuralnetworks/1.3/types.hal
index c5dc08c..530f984 100644
--- a/neuralnetworks/1.3/types.hal
+++ b/neuralnetworks/1.3/types.hal
@@ -2556,6 +2556,30 @@
      *      A 3-D tensor of shape:
      *        If time-major: [max_time, batch_size, bw_output_size]
      *        If batch-major: [batch_size, max_time, bw_output_size]
+     * * 2: The forward activation state output.
+     *      A 2-D tensor of shape [batch_size, fw_output_size] containing an
+     *      activation state from the last time step in the sequence. This
+     *      output is optional and can be omitted. If this output is present
+     *      then outputs 3-5 must be present as well.
+     *      Available since HAL version 1.3.
+     * * 3: The forward cell state output.
+     *      A tensor of shape [batch_size, fw_cell_size] containing a cell state
+     *      from the last time step in the sequence. This output is optional
+     *      and can be omitted. If this output is present
+     *      then outputs 2, 4, 5 must be present as well.
+     *      Available since HAL version 1.3.
+     * * 4: The backward activation state output.
+     *      A 2-D tensor of shape [batch_size, bw_output_size] containing an
+     *      activation state from the last time step in the sequence. This
+     *      output is optional and can be omitted. If this output is present
+     *      then outputs 2, 3, 5 must be present as well.
+     *      Available since HAL version 1.3.
+     * * 5: The backward cell state output.
+     *      A tensor of shape [batch_size, bw_cell_size] containing a cell state
+     *      from the last time step in the sequence. This output is optional
+     *      and can be omitted. If this output is present
+     *      then outputs 2-4 must be present as well.
+     *      Available since HAL version 1.3.
      */
     BIDIRECTIONAL_SEQUENCE_LSTM = @1.2::OperationType:BIDIRECTIONAL_SEQUENCE_LSTM,
 
@@ -2673,6 +2697,18 @@
      *      (timeMajor). If it is set to true, then the shape is set to
      *      [maxTime, batchSize, bwNumUnits], otherwise the shape is set to
      *      [batchSize, maxTime, bwNumUnits].
+     * * 2: The forward hidden state output.
+     *      A 2-D tensor of shape [batchSize, fwNumUnits] containing a hidden
+     *      state from the last time step in the sequence. This output is
+     *      optional and can be omitted. If this output is present then output
+     *      3 must be present as well.
+     *      Available since HAL version 1.3.
+     * * 3: The backward hidden state output.
+     *      A 2-D tensor of shape [batchSize, bwNumUnits] containing a hidden
+     *      state from the last time step in the sequence. This output is
+     *      optional and can be omitted. If this output is present then output
+     *      2 must be present as well.
+     *      Available since HAL version 1.3.
      */
     BIDIRECTIONAL_SEQUENCE_RNN = @1.2::OperationType:BIDIRECTIONAL_SEQUENCE_RNN,
 
@@ -4656,6 +4692,15 @@
      *      A 3-D tensor of shape:
      *        If time-major: [max_time, batch_size, output_size]
      *        If batch-major: [batch_size, max_time, output_size]
+     * * 1: A tensor of shape [batch_size, output_size] containing a hidden
+     *      state from the last time step in the sequence. This output is
+     *      optional and can be omitted. If this output is present then
+     *      output #2 must be present as well.
+     *      Available since HAL version 1.3.
+     * * 2: A tensor of shape [batch_size, cell_size] containing a cell state
+     *      from the last time step in the sequence. This output is optional
+     *      and can be omitted.
+     *      Available since HAL version 1.3.
      */
     UNIDIRECTIONAL_SEQUENCE_LSTM = @1.2::OperationType:UNIDIRECTIONAL_SEQUENCE_LSTM,
 
@@ -4711,6 +4756,10 @@
      *      it is set to 1, then the output has a shape [maxTime, batchSize,
      *      numUnits], otherwise the output has a shape [batchSize, maxTime,
      *      numUnits].
+     * * 1: A tensor of shape [batchSize, numUnits] containing hidden state
+     *      from the last time step in the sequence. This output is optional
+     *      and can be omitted.
+     *      Available since HAL version 1.3.
      */
     UNIDIRECTIONAL_SEQUENCE_RNN = @1.2::OperationType:UNIDIRECTIONAL_SEQUENCE_RNN,
 
diff --git a/neuralnetworks/1.3/vts/functional/ValidateModel.cpp b/neuralnetworks/1.3/vts/functional/ValidateModel.cpp
index 0a35e2d..b9ea430 100644
--- a/neuralnetworks/1.3/vts/functional/ValidateModel.cpp
+++ b/neuralnetworks/1.3/vts/functional/ValidateModel.cpp
@@ -527,9 +527,15 @@
                 }
             }
         }
-        // BIDIRECTIONAL_SEQUENCE_LSTM and BIDIRECTIONAL_SEQUENCE_RNN can have either one or two
-        // outputs depending on their mergeOutputs parameter.
-        if (operation.type == OperationType::BIDIRECTIONAL_SEQUENCE_LSTM ||
+        // BIDIRECTIONAL_SEQUENCE_LSTM and BIDIRECTIONAL_SEQUENCE_RNN can have
+        // either one, two, three or four outputs depending on their
+        // mergeOutputs parameter and if state outputs are provided.
+        // UNIDIRECTIONAL_SEQUENCE_LSTM and UNIDIRECTIONAL_SEQUENCE_RNN can have
+        // either one or three outputs depending on whether state outputs are
+        // provided.
+        if (operation.type == OperationType::UNIDIRECTIONAL_SEQUENCE_LSTM ||
+            operation.type == OperationType::UNIDIRECTIONAL_SEQUENCE_RNN ||
+            operation.type == OperationType::BIDIRECTIONAL_SEQUENCE_LSTM ||
             operation.type == OperationType::BIDIRECTIONAL_SEQUENCE_RNN) {
             for (const size_t outOprand : operation.outputs) {
                 if (operand == outOprand) {