diff --git a/src/core/default-value.h b/src/core/default-value.h
index 299d21102..f57b3b4e0 100644
--- a/src/core/default-value.h
+++ b/src/core/default-value.h
@@ -135,7 +135,7 @@ private:
 };
 
 /**
- * \brief An Numeric variable for ns3::Bind
+ * \brief A Numeric variable for ns3::Bind
  * \ingroup config
  *
  * Every instance of this type is automatically