diff --git a/integrationTests/ts/basic-test.ts b/integrationTests/ts/basic-test.ts
index 76b92a0c0a..a28bd840e7 100644
--- a/integrationTests/ts/basic-test.ts
+++ b/integrationTests/ts/basic-test.ts
@@ -9,10 +9,13 @@ const queryType: GraphQLObjectType = new GraphQLObjectType({
     sayHi: {
       type: GraphQLString,
       args: {
-        who: { type: GraphQLString },
+        who: {
+          type: GraphQLString,
+          defaultValue: 'World',
+        },
       },
-      resolve(_root, args) {
-        return 'Hello ' + (args.who ?? 'World');
+      resolve(_root, args: { who: string }) {
+        return 'Hello ' + args.who;
       },
     },
   }),
diff --git a/src/type/definition.ts b/src/type/definition.ts
index b7ca3ce36c..ed658a8fc7 100644
--- a/src/type/definition.ts
+++ b/src/type/definition.ts
@@ -962,7 +962,7 @@ export type GraphQLIsTypeOfFn<TSource, TContext> = (
 export type GraphQLFieldResolver<
   TSource,
   TContext,
-  TArgs = { [argument: string]: any },
+  TArgs = any,
   TResult = unknown,
 > = (
   source: TSource,
@@ -996,19 +996,11 @@ export interface GraphQLResolveInfo {
  * We've provided these template arguments because this is an open type and
  * you may find them useful.
  */
-export interface GraphQLFieldExtensions<
-  _TSource,
-  _TContext,
-  _TArgs = { [argName: string]: any },
-> {
+export interface GraphQLFieldExtensions<_TSource, _TContext, _TArgs = any> {
   [attributeName: string]: unknown;
 }
 
-export interface GraphQLFieldConfig<
-  TSource,
-  TContext,
-  TArgs = { [argument: string]: any },
-> {
+export interface GraphQLFieldConfig<TSource, TContext, TArgs = any> {
   description?: Maybe<string>;
   type: GraphQLOutputType;
   args?: GraphQLFieldConfigArgumentMap;
@@ -1049,11 +1041,7 @@ export type GraphQLFieldConfigMap<TSource, TContext> = ObjMap<
   GraphQLFieldConfig<TSource, TContext>
 >;
 
-export interface GraphQLField<
-  TSource,
-  TContext,
-  TArgs = { [argument: string]: any },
-> {
+export interface GraphQLField<TSource, TContext, TArgs = any> {
   name: string;
   description: Maybe<string>;
   type: GraphQLOutputType;