diff --git a/Tools/px4moduledoc/srcparser.py b/Tools/px4moduledoc/srcparser.py
index cd4b029f95..00b2e6ab04 100644
--- a/Tools/px4moduledoc/srcparser.py
+++ b/Tools/px4moduledoc/srcparser.py
@@ -128,7 +128,7 @@ class ModuleDocumentation(object):
         self._paring_implicit_options = True
         if self._is_bool_true(args[0]):
             self._handle_usage_param_flag(['\'I\'', "\"Internal I2C bus(es)\"", 'true'])
-            self._handle_usage_param_flag(['\'X\'', "\"External I2C bus(es\")", 'true'])
+            self._handle_usage_param_flag(['\'X\'', "\"External I2C bus(es)\"", 'true'])
         if self._is_bool_true(args[1]):
             self._handle_usage_param_flag(['\'s\'', "\"Internal SPI bus(es)\"", 'true'])
             self._handle_usage_param_flag(['\'S\'', "\"External SPI bus(es)\"", 'true'])