diff --git a/rosidl_runtime_py/set_message.py b/rosidl_runtime_py/set_message.py
index 5e7921e..aa62074 100644
--- a/rosidl_runtime_py/set_message.py
+++ b/rosidl_runtime_py/set_message.py
@@ -28,7 +28,7 @@
 
 
 def set_message_fields(
-        msg: Any, values: Dict[str, str], expand_header_auto: bool = False,
+        msg: Any, values: Dict[str, Any], expand_header_auto: bool = False,
         expand_time_now: bool = False) -> List[Any]:
     """
     Set the fields of a ROS message.
@@ -52,7 +52,7 @@ def set_message_fields(
     timestamp_fields = []
 
     def set_message_fields_internal(
-            msg: Any, values: Dict[str, str],
+            msg: Any, values: Dict[str, Any],
             timestamp_fields: List[Any]) -> List[Any]:
         try:
             items = values.items()
@@ -70,6 +70,10 @@ def set_message_fields_internal(
                 value = numpy.array(field_value, dtype=field.dtype)
             elif type(field_value) is field_type:
                 value = field_value
+            elif field_type is bytes and type(field_value) is str:
+                # value = field_value.encode()
+                value = bytes([ord(c) for c in field_value])
+                # value = bytes(field_value, 'ascii', 'backslashreplace')
             # We can't import these types directly, so we use the qualified class name to
             # distinguish them from other fields
             elif qualified_class_name == 'std_msgs.msg._header.Header' and \
diff --git a/test/rosidl_runtime_py/test_set_message.py b/test/rosidl_runtime_py/test_set_message.py
index 9c39f09..093285e 100644
--- a/test/rosidl_runtime_py/test_set_message.py
+++ b/test/rosidl_runtime_py/test_set_message.py
@@ -14,11 +14,12 @@
 
 import builtins
 import copy
+import yaml
 
 from builtin_interfaces.msg import Time
 import pytest
 import rosidl_parser.definition
-from rosidl_runtime_py import set_message_fields
+from rosidl_runtime_py import set_message_fields, message_to_yaml
 from std_msgs.msg import Header
 from test_msgs import message_fixtures
 
@@ -140,6 +141,18 @@ def test_set_message_fields_partial():
             assert getattr(modified_msg, attr) == getattr(original_msg, attr)
 
 
+def test_set_message_fields_from_yaml():
+    original_msg = message_fixtures.get_msg_basic_types()[1]
+    original_yaml = message_to_yaml(original_msg)
+    values = yaml.safe_load(original_yaml)
+
+    modified_msg = copy.copy(message_fixtures.get_msg_basic_types()[0])
+    set_message_fields(modified_msg, values)
+
+    for attr in original_msg.get_fields_and_field_types().keys():
+        assert getattr(modified_msg, attr) == getattr(original_msg, attr)
+
+
 def test_set_message_fields_full():
     msg_list = message_fixtures.get_msg_basic_types()
     msg0 = msg_list[0]