diff --git a/pkg/analyzer/lib/src/summary2/linked_unit_context.dart b/pkg/analyzer/lib/src/summary2/linked_unit_context.dart
index 0adb942..36c9d9d 100644
--- a/pkg/analyzer/lib/src/summary2/linked_unit_context.dart
+++ b/pkg/analyzer/lib/src/summary2/linked_unit_context.dart
@@ -431,7 +431,7 @@
     } else if (node is EnumConstantDeclaration) {
       return node.name.offset;
     } else if (node is FormalParameter) {
-      return node.identifier.offset;
+      return node.identifier?.offset ?? -1;
     } else if (node is MethodDeclaration) {
       return node.name.offset;
     } else if (node is NamedCompilationUnitMember) {