diff --git a/types/accept-language-parser/accept-language-parser-tests.ts b/types/accept-language-parser/accept-language-parser-tests.ts
index ce34f044bf..b137df02e4 100644
--- a/types/accept-language-parser/accept-language-parser-tests.ts
+++ b/types/accept-language-parser/accept-language-parser-tests.ts
@@ -20,6 +20,6 @@ const l3: AcceptLanguageParser.Language = {
     quality: 0.9
 };
 
-AcceptLanguageParser.parse('');
-AcceptLanguageParser.pick([''], '');
-AcceptLanguageParser.pick([''], [l1, l2, l3]);
+const parsed1: AcceptLanguageParser.Language[] = AcceptLanguageParser.parse('');
+const pick1: string | null = AcceptLanguageParser.pick([''], '');
+const pick2: string | null = AcceptLanguageParser.pick([''], [l1, l2, l3]);
diff --git a/types/accept-language-parser/index.d.ts b/types/accept-language-parser/index.d.ts
index 6dbb1c7578..16d003648c 100644
--- a/types/accept-language-parser/index.d.ts
+++ b/types/accept-language-parser/index.d.ts
@@ -7,7 +7,7 @@
 // https://github.com/opentable/accept-language-parser/blob/v1.4.1/index.js
 
 export function parse(acceptLanguage: string): Language[];
-export function pick(supportedLanguages: string[], acceptLanguage: string | Language[]): Language | null;
+export function pick(supportedLanguages: string[], acceptLanguage: string | Language[]): string | null;
 
 export interface Language {
     code: string;