diff --git a/src/Lean/Parser/Types.lean b/src/Lean/Parser/Types.lean
index fa6a7f83ed..c0e215e6c6 100644
--- a/src/Lean/Parser/Types.lean
+++ b/src/Lean/Parser/Types.lean
@@ -201,6 +201,7 @@ structure ParserState where
 
 namespace ParserState
 
+@[inline]
 def hasError (s : ParserState) : Bool :=
   s.errorMsg != none