diff --git a/rosidl_generator_py/cmake/rosidl_generator_py_generate_interfaces.cmake b/rosidl_generator_py/cmake/rosidl_generator_py_generate_interfaces.cmake
index c351ec09..3fe17b02 100644
--- a/rosidl_generator_py/cmake/rosidl_generator_py_generate_interfaces.cmake
+++ b/rosidl_generator_py/cmake/rosidl_generator_py_generate_interfaces.cmake
@@ -399,7 +399,8 @@ if(BUILD_TESTING AND rosidl_generate_interfaces_ADD_LINTER_TESTS)
     ament_uncrustify(
       TESTNAME "uncrustify_rosidl_generated_py"
       # the generated code might contain longer lines for templated types
-      MAX_LINE_LENGTH 999
+      # a value of zero tells uncrustify to ignore line length
+      MAX_LINE_LENGTH 0
       "${_output_path}")
   endif()
 endif()