diff --git a/src/utilities/lexicographicSortSchema.d.ts b/src/utilities/lexicographicSortSchema.d.ts
index 0cba04c0e8..7dfde701d7 100644
--- a/src/utilities/lexicographicSortSchema.d.ts
+++ b/src/utilities/lexicographicSortSchema.d.ts
@@ -2,5 +2,7 @@ import { GraphQLSchema } from '../type/schema';
 
 /**
  * Sort GraphQLSchema.
+ *
+ * This function returns a sorted copy of the given GraphQLSchema.
  */
 export function lexicographicSortSchema(schema: GraphQLSchema): GraphQLSchema;
diff --git a/src/utilities/lexicographicSortSchema.js b/src/utilities/lexicographicSortSchema.js
index ded7abd48c..c9b932f5f7 100644
--- a/src/utilities/lexicographicSortSchema.js
+++ b/src/utilities/lexicographicSortSchema.js
@@ -31,6 +31,8 @@ import {
 
 /**
  * Sort GraphQLSchema.
+ *
+ * This function returns a sorted copy of the given GraphQLSchema.
  */
 export function lexicographicSortSchema(schema: GraphQLSchema): GraphQLSchema {
   const schemaConfig = schema.toConfig();