diff --git a/scalecodec/types.py b/scalecodec/types.py
index 5f0a205..9e9e6cf 100644
--- a/scalecodec/types.py
+++ b/scalecodec/types.py
@@ -1957,6 +1957,22 @@ def process_encode(self, value):
 
         else:
 
+            if type(value) is str:
+                if value[0:2] != '0x':
+                    raise ValueError('Give the value is not from 0x')
+                elif self.runtime_config.get_decoder_class(self.sub_type) is U16 and len(value[2:]) != self.element_count * 4:
+                    raise ValueError('Value should be {} bytes long'.format(self.element_count))
+                elif self.runtime_config.get_decoder_class(self.sub_type) is U32 and len(value[2:]) != self.element_count * 8:
+                    raise ValueError('Value should be {} bytes long'.format(self.element_count))
+                elif self.runtime_config.get_decoder_class(self.sub_type) is U64 and len(value[2:]) != self.element_count * 16:
+                    raise ValueError('Value should be {} bytes long'.format(self.element_count))
+                elif self.runtime_config.get_decoder_class(self.sub_type) is U128 and len(value[2:]) != self.element_count * 32:
+                    raise ValueError('Value should be {} bytes long'.format(self.element_count))
+                elif self.runtime_config.get_decoder_class(self.sub_type) is U256 and len(value[2:]) != self.element_count * 64:
+                    raise ValueError('Value should be {} bytes long'.format(self.element_count))
+                else:
+                    return ScaleBytes(value)
+
             if not type(value) is list:
                 raise ValueError('Given value is not a list')
 
diff --git a/test/test_scale_types.py b/test/test_scale_types.py
index bb96019..44b250d 100644
--- a/test/test_scale_types.py
+++ b/test/test_scale_types.py
@@ -364,6 +364,9 @@ def test_dynamic_fixed_array_type_decode(self):
         obj = RuntimeConfiguration().create_scale_object('[u32; 0]', data=ScaleBytes(bytes()))
         self.assertEqual([], obj.decode())
 
+        obj = RuntimeConfiguration().create_scale_object('[u64; 3]', data=ScaleBytes("0x010000000000000002000000000000000300000000000000"))
+        self.assertEqual([1, 2, 3], obj.decode())
+
     def test_dynamic_fixed_array_type_decode_u8(self):
         obj = RuntimeConfiguration().create_scale_object('[u8; 65]', data=ScaleBytes("0xc42b82d02bce3202f6a05d4b06d1ad46963d3be36fd0528bbe90e7f7a4e5fcd38d14234b1c9fcee920d76cfcf43b4ed5dd718e357c2bc1aae3a642975207e67f01"))
         self.assertEqual('0xc42b82d02bce3202f6a05d4b06d1ad46963d3be36fd0528bbe90e7f7a4e5fcd38d14234b1c9fcee920d76cfcf43b4ed5dd718e357c2bc1aae3a642975207e67f01', obj.decode())
@@ -381,6 +384,15 @@ def test_dynamic_fixed_array_type_encode(self):
         obj = RuntimeConfiguration().create_scale_object('[u8; 3]')
         self.assertEqual('0x010203', str(obj.encode('0x010203')))
 
+        obj = RuntimeConfiguration().create_scale_object('[u64; 1]')
+        self.assertEqual('0x01000000000000000200000000000000', str(obj.encode([1, 2])))
+
+        obj = RuntimeConfiguration().create_scale_object('[u64; 3]')
+        self.assertEqual('0x010000000000000002000000000000000300000000000000', str(obj.encode([1, 2, 3])))
+
+        obj = RuntimeConfiguration().create_scale_object('[u64; 3]')
+        self.assertEqual('0x010000000000000002000000000000000300000000000000', str(obj.encode('0x010000000000000002000000000000000300000000000000')))
+
     def test_invalid_fixed_array_type_encode(self):
         obj = RuntimeConfiguration().create_scale_object('[u8; 3]')
         self.assertRaises(ValueError, obj.encode, '0x0102')
@@ -388,6 +400,9 @@ def test_invalid_fixed_array_type_encode(self):
         obj = RuntimeConfiguration().create_scale_object('[u32; 3]')
         self.assertRaises(ValueError, obj.encode, '0x0102')
 
+        obj = RuntimeConfiguration().create_scale_object('[u64; 3]')
+        self.assertRaises(ValueError, obj.encode, '0x0102')
+
     def test_custom_tuple(self):
         obj = RuntimeConfiguration().create_scale_object('(u8,u8)', ScaleBytes("0x0102"))
         self.assertEqual((1, 2), obj.decode())