diff --git a/grammar/AST.asdl b/grammar/AST.asdl
index 88d64df00c..e0e46bc7ee 100644
--- a/grammar/AST.asdl
+++ b/grammar/AST.asdl
@@ -1,4 +1,4 @@
--- This is an Abstract Syntax Description Lanuguage (ASDL) that describes the
+-- This is an Abstract Syntax Description Language (ASDL) that describes the
 -- Fortran's Abstract Syntax Tree (AST). See [1] for a short background
 -- information and motivation and see the paper [2] for a detailed motivation,
 -- explanation and specification of the language. See [3] for further examples