diff --git a/rosidl_generator_c/msg/PrimitiveValues.msg b/rosidl_generator_c/msg/PrimitiveValues.msg
index 7a14ebd0f..b803e7bef 100644
--- a/rosidl_generator_c/msg/PrimitiveValues.msg
+++ b/rosidl_generator_c/msg/PrimitiveValues.msg
@@ -1,7 +1,7 @@
 bool def_bool_1 true
 bool def_bool_2 false
 byte def_byte 66
-char def_char 67
+char def_char -66
 float32 def_float32 1.125
 float64 def_float64 1.125
 int8 def_int8 3
diff --git a/rosidl_generator_c/rosidl_generator_c/__init__.py b/rosidl_generator_c/rosidl_generator_c/__init__.py
index cba61bc34..848f85307 100644
--- a/rosidl_generator_c/rosidl_generator_c/__init__.py
+++ b/rosidl_generator_c/rosidl_generator_c/__init__.py
@@ -166,7 +166,7 @@ def primitive_value_to_c(type_, value):
     if type_ == 'bool':
         return 'true' if value else 'false'
 
-    if type_ in ['byte', 'char', 'signed char', 'int8', 'int16', 'int32', 'int64']:
+    if type_ in ['byte', 'char', 'int8', 'int16', 'int32', 'int64']:
         return str(value)
 
     if type_ in ['uint8', 'uint16', 'uint32', 'uint64']:
diff --git a/rosidl_generator_c/test/test_interfaces.c b/rosidl_generator_c/test/test_interfaces.c
index 309661337..07872c8fb 100644
--- a/rosidl_generator_c/test/test_interfaces.c
+++ b/rosidl_generator_c/test/test_interfaces.c
@@ -255,7 +255,7 @@ int test_primitives_default_value(void)
   EXPECT_EQ(true, primitive_values->def_bool_1);
   EXPECT_EQ(false, primitive_values->def_bool_2);
   EXPECT_EQ(66, primitive_values->def_byte);
-  EXPECT_EQ(67, primitive_values->def_char);
+  EXPECT_EQ(-66, primitive_values->def_char);
   EXPECT_EQ(1.125f, primitive_values->def_float32);
   EXPECT_EQ(1.125, primitive_values->def_float64);
   EXPECT_EQ(3, primitive_values->def_int8);