diff --git a/.prettierignore b/.prettierignore
index 5e3434855df..548792bb901 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -14,6 +14,9 @@ packages/ast-spec/src/*/*/fixtures/_error_/*/fixture.ts
 # prettier doesn't yet support auto-accessors
 packages/ast-spec/src/element/AccessorProperty/fixtures
 
+# prettier doesn't yet support `const` modifiers for type parameters
+packages/ast-spec/src/special/TSTypeParameter/fixtures
+
 # Ignore CHANGELOG.md files to avoid issues with automated release job
 CHANGELOG.md