diff --git a/src/Lean/Message.lean b/src/Lean/Message.lean
index a6f5676402..1f3eb81077 100644
--- a/src/Lean/Message.lean
+++ b/src/Lean/Message.lean
@@ -37,7 +37,7 @@ structure NamingContext where
   currNamespace : Name
   openDecls : List OpenDecl
 
-/-- Structure message data. We use it for reporting errors, trace messages, etc. -/
+/-- Structured message data. We use it for reporting errors, trace messages, etc. -/
 inductive MessageData where
   | ofFormat          : Format → MessageData
   | ofSyntax          : Syntax → MessageData