diff --git a/src/type/definition.ts b/src/type/definition.ts
index a9e0d86836..05cfa430de 100644
--- a/src/type/definition.ts
+++ b/src/type/definition.ts
@@ -1187,7 +1187,7 @@ export interface GraphQLInterfaceTypeConfig<TSource, TContext> {
   extensionASTNodes?: Maybe<ReadonlyArray<InterfaceTypeExtensionNode>>;
 }
 
-export interface GraphQLInterfaceTypeNormalizedConfig<TSource, TContext>
+interface GraphQLInterfaceTypeNormalizedConfig<TSource, TContext>
   extends GraphQLInterfaceTypeConfig<any, any> {
   interfaces: ReadonlyArray<GraphQLInterfaceType>;
   fields: GraphQLFieldConfigMap<TSource, TContext>;