diff --git a/lib/graphql/analysis/query_complexity.rb b/lib/graphql/analysis/query_complexity.rb
index 1cf1c48cf52..4a90824b4c4 100644
--- a/lib/graphql/analysis/query_complexity.rb
+++ b/lib/graphql/analysis/query_complexity.rb
@@ -35,7 +35,7 @@ def result
               complexity_cost_calculation_mode(:future) # or `:legacy`, `:compare`
 
           GRAPHQL
-          max_possible_complexity
+          max_possible_complexity(mode: :legacy)
         else
           raise ArgumentError, "Expected `:future`, `:legacy`, `:compare`, or `nil` from `#{query.schema}.complexity_cost_calculation_mode_for` but got: #{query.schema.complexity_cost_calculation_mode.inspect}"
         end
diff --git a/spec/graphql/analysis/query_complexity_spec.rb b/spec/graphql/analysis/query_complexity_spec.rb
index 2afd152e504..818ea5b596b 100644
--- a/spec/graphql/analysis/query_complexity_spec.rb
+++ b/spec/graphql/analysis/query_complexity_spec.rb
@@ -958,6 +958,30 @@ def self.legacy_complexity_cost_calculation_mismatch(query, future_cpx, legacy_c
 
         assert_includes stdout, "GraphQL-Ruby's complexity cost system is getting some \"breaking fixes\" in a future version. See the migration notes at https://graphql-ruby.org/api-doc/#{GraphQL::VERSION}/GraphQL/Schema.html#complexity_cost_calculation_mode_for-class_method
 
+To opt into the future behavior, configure your schema (MaxOfPossibleScopes) with:
+
+  complexity_cost_calculation_mode(:future) # or `:legacy`, `:compare`"
+      end
+
+      it "uses legacy mode" do
+        cost = nil
+        assert_nil MaxOfPossibleScopes.complexity_cost_calculation_mode
+        stdout, _stderr = capture_io do
+          cost = MaxOfPossibleScopes.cost(%|
+            {
+              entity {
+                ...on Farm { name }
+                ...on Producer { name }
+              }
+            }
+          |)
+        end
+        puts stdout
+
+        assert_equal 6, cost
+
+        assert_includes stdout, "GraphQL-Ruby's complexity cost system is getting some \"breaking fixes\" in a future version. See the migration notes at https://graphql-ruby.org/api-doc/#{GraphQL::VERSION}/GraphQL/Schema.html#complexity_cost_calculation_mode_for-class_method
+
 To opt into the future behavior, configure your schema (MaxOfPossibleScopes) with:
 
   complexity_cost_calculation_mode(:future) # or `:legacy`, `:compare`"