diff --git a/ethosu/vela/supported_operators.py b/ethosu/vela/supported_operators.py
index 1bebe9a..99a4ba1 100644
--- a/ethosu/vela/supported_operators.py
+++ b/ethosu/vela/supported_operators.py
@@ -87,7 +87,7 @@
         set((Op.ReduceSum, Op.CLZ,)) | binary_elem_wise_add_mul_sub | binary_elem_wise_shift_ops
     )
     relu_ops = Op.op_set(Op.is_relu_op)
-    activation_ops = relu_ops | set((Op.Tanh, Op.Sigmoid, Op.Softmax,))
+    activation_ops = relu_ops | set((Op.Tanh, Op.Sigmoid, Op.Softmax, Op.HardSwish))
     npu_post_ops = (
         # activation functions
         activation_ops
@@ -261,6 +261,10 @@
         self.specific_constraints[Op.Pad].append(SupportedOperators.constraint_pad_constant)
         self.specific_constraints[Op.Pad].append(SupportedOperators.constraint_pad_ofm)
 
+        # HardSwish specific checks:
+        self.specific_constraints[Op.HardSwish].append(SupportedOperators.constraint_input_8bit)
+        self.specific_constraints[Op.HardSwish].append(SupportedOperators.constraint_matching_in_out_types)
+
     def is_operator_supported(self, op):
         ext_type = optype_to_builtintype(op.type)
         if op.type not in SupportedOperators.supported_operators:
@@ -934,6 +938,13 @@
         return valid, f"Op has ofm_dtype={ofm_dtype}"
 
     @staticmethod
+    def constraint_input_8bit(op):
+        "IFM must be int8 or uint8"
+        ifm_dtype = op.ifm.dtype
+        valid = (ifm_dtype == DataType.int8) or (ifm_dtype == DataType.uint8)
+        return valid, f"Op has ifm_dtype={ifm_dtype}"
+
+    @staticmethod
     def constraint_matching_quantization_parameters(op):
         "Both Input quantization parameters must match OFM quantization parameters"
         valid = True