diff --git a/.prettierignore b/.prettierignore
index d681ddb3e42..e36c8f8cb2a 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -4,6 +4,3 @@
 working-group/
 packages/codemirror-graphql/src/__tests__/schema-kitchen-sink.graphql
 CHANGELOG.md
-
-# remove after merge of https://github.com/graphql/graphiql/pull/3256
-*.flow
diff --git a/packages/graphql-language-service/src/interface/index.js.flow b/packages/graphql-language-service/src/interface/index.js.flow
deleted file mode 100644
index 8b856056bdf..00000000000
--- a/packages/graphql-language-service/src/interface/index.js.flow
+++ /dev/null
@@ -1,94 +0,0 @@
-/**
- *  Copyright (c) 2021 GraphQL Contributors
- *  All rights reserved.
- *
- *  This source code is licensed under the license found in the
- *  LICENSE file in the root directory of this source tree.
- *
- *  @flow
- */
-
-import type {
-  Outline,
-  Diagnostic,
-  ContextToken,
-  ContextTokenUnion,
-  IPosition,
-  DefinitionQueryResult,
-  Uri,
-  GraphQLCache,
-  CompletionItem,
-  CompletionItemBase,
-  TypeInfo,
-  State,
-} from 'graphql-language-service';
-import type { ValidationRule, GraphQLSchema } from 'graphql';
-import type { Hover } from 'vscode-languageserver-types';
-import { GraphQLDirective } from "graphql";
-import type { FragmentDefinitionNode } from "graphql";
-
-declare export function getOutline(queryText: string): ?Outline;
-declare export function getDiagnostics(
-  query: string,
-  schema: ?GraphQLSchema,
-  customRules?: Array<ValidationRule>,
-  isRelayCompatMode?: boolean,
-  externalFragments?: Array<FragmentDefinitionNode> | string
-): Array<Diagnostic>;
-
-declare export function getAutocompleteSuggestions(
-  schema: GraphQLSchema,
-  queryText: string,
-  cursor: IPosition,
-  contextToken?: ContextToken,
-  externalFragments?: Array<FragmentDefinitionNode>
-): Array<CompletionItem>;
-
-declare export class GraphQLLanguageService {
-  constructor(cache: GraphQLCache): GraphQLLanguageService;
-
-  getDefinition(
-    query: string,
-    position: IPosition,
-    filePath: Uri,
-  ): Promise<?DefinitionQueryResult>;
-
-  getDiagnostics(
-    query: string,
-    uri: Uri,
-    isRelayCompatMode?: boolean,
-  ): Promise<Array<Diagnostic>>;
-
-  getHoverInformation(
-    query: string,
-    position: IPosition,
-    filePath: Uri,
-  ): Promise<Hover.contents>;
-
-  getAutocompleteSuggestions(
-    query: string,
-    position: IPosition,
-    filePath: Uri,
-  ): Promise<Array<CompletionItem>>;
-}
-declare export function canUseDirective(
-  state: $PropertyType<State, "prevState">,
-  directive: GraphQLDirective
-): boolean;
-declare export function getDefinitionState(
-  tokenState: State
-): State | null | void;
-declare export function getFragmentDefinitions(
-  queryText: string
-): Array<FragmentDefinitionNode>;
-declare export function getTypeInfo(
-  schema: GraphQLSchema,
-  tokenState: State
-): TypeInfo;
-declare export function hintList<T: CompletionItemBase>(
-  token: ContextTokenUnion,
-  list: Array<T>
-): Array<T>;
-declare export function objectValues(object: {
-  [key: string]: any,
-}): Array<any>;
diff --git a/packages/graphql-language-service/src/utils/index.js.flow b/packages/graphql-language-service/src/utils/index.js.flow
deleted file mode 100644
index 5dfe519b675..00000000000
--- a/packages/graphql-language-service/src/utils/index.js.flow
+++ /dev/null
@@ -1,33 +0,0 @@
-/**
- *  Copyright (c) 2021 GraphQL Contributors
- *  All rights reserved.
- *
- *  This source code is licensed under the license found in the
- *  LICENSE file in the root directory of this source tree.
- *
- *  @flow
- */
-
-import type { Location } from 'graphql/language';
-
-import type {
-  IRange,
-  IPosition ,
-} from 'graphql-language-service';
-
-declare export function getASTNodeAtPosition(): void;
-
-declare export class Position implements IPosition {
-  line: number;
-  character: number;
-  constructor(row: number, column: number): IPosition;
-  lessThanOrEqualTo: (position: IPosition) => boolean;
-}
-
-declare export class Range implements IRange {
-  start: IPosition;
-  end: IPosition;
-  constructor(start: IPosition, end: IPosition): IRange;
-  containsPosition: (position: IPosition) => boolean;
-}
-