diff --git a/src/parser/ast.yaml b/src/parser/ast.yaml
index b46483f..36d1fb4 100644
--- a/src/parser/ast.yaml
+++ b/src/parser/ast.yaml
@@ -305,6 +305,8 @@ Function:
         skip: true
     - generics:
         rule: GenericParameters
+        build:
+          or_else_default: true
     - identifier
     - parameters
     - return_type: