diff --git a/types/graphql/validation/specifiedRules.d.ts b/types/graphql/validation/specifiedRules.d.ts
index f6ff475674..c7c177b00e 100644
--- a/types/graphql/validation/specifiedRules.d.ts
+++ b/types/graphql/validation/specifiedRules.d.ts
@@ -86,5 +86,7 @@ import { UniqueInputFieldNames } from "./rules/UniqueInputFieldNames";
  */
 export const specifiedRules: ReadonlyArray<ValidationRule>;
 
+import { LoneSchemaDefinition } from "./rules/LoneSchemaDefinition";
+
 // @internal
 export const specifiedSDLRules: ReadonlyArray<SDLValidationRule>;