diff --git a/scrapy/utils/conf.py b/scrapy/utils/conf.py
index 24873f75d..24a6187b9 100644
--- a/scrapy/utils/conf.py
+++ b/scrapy/utils/conf.py
@@ -164,7 +164,7 @@ def feed_process_params_from_cli(settings, output, output_format=None,
             message = (
                 'The -t command line option is deprecated in favor of '
                 'specifying the output format within the output URI. See the '
-                'documentation of the -o and -O options for more information.',
+                'documentation of the -o and -O options for more information.'
             )
             warnings.warn(message, ScrapyDeprecationWarning, stacklevel=2)
             return {output[0]: {'format': output_format}}