diff --git a/src/ros2cs/rosidl_generator_cs/rosidl_generator_cs/generate_cs_impl.py b/src/ros2cs/rosidl_generator_cs/rosidl_generator_cs/generate_cs_impl.py
index 54739267..134a4880 100644
--- a/src/ros2cs/rosidl_generator_cs/rosidl_generator_cs/generate_cs_impl.py
+++ b/src/ros2cs/rosidl_generator_cs/rosidl_generator_cs/generate_cs_impl.py
@@ -113,7 +113,7 @@ def get_marshal_type(type_):
     'boolean': 'byte',
     'octet': 'byte',
     'uint8': 'byte',
-    'int8': 'char',
+    'int8': 'byte',
     'uint16': 'short',
     'int16': 'short',
     'uint32': 'int',