diff --git a/services/web/frontend/js/features/source-editor/lezer-typst/typst.grammar b/services/web/frontend/js/features/source-editor/lezer-typst/typst.grammar
index f7e05a5ba3..f2ee06cb71 100644
--- a/services/web/frontend/js/features/source-editor/lezer-typst/typst.grammar
+++ b/services/web/frontend/js/features/source-editor/lezer-typst/typst.grammar
@@ -222,7 +222,11 @@ Escape { "\\" EscapeChar }
   // "(" > "." > "]" > text tokens: after '#' CodeIdent, callSuffix delimiters
   //   must win over MarkupContent/StrongText/EmphText in merged states.
   // LineCommentContent and MathContent are external tokens — not listed here.
-  @precedence { CodeKeyword CodeBool CodeIdent EscapeChar "(" "." "]" spaces MarkupContent StrongText EmphText }
+  // "_" added after CodeIdent: KeywordExpr { CodeKeyword CallExpr? } merges
+  // the post-keyword state with markup states where "_" starts Emphasis.
+  // CodeIdent wins so '#set _name(...)' is tokenised correctly; in pure markup
+  // states CodeIdent is not in the valid set so "_" still opens Emphasis.
+  @precedence { CodeKeyword CodeBool CodeIdent EscapeChar "(" "." "]" "_" spaces MarkupContent StrongText EmphText }
 }
 
 @skip { spaces }