diff --git a/README.md b/README.md
index 08c4ae9..279c908 100644
--- a/README.md
+++ b/README.md
@@ -82,7 +82,8 @@ information.
   "publisher": "Macmillan",
   "publishedDate": "2014-02-04",
   "language": "en",
-  "isbn": "9780374104092"
+  "isbn": "9780374104092",
+  "bookProvider": "Google Books"
 }
 ```
 
@@ -146,7 +147,8 @@ information.
   "publisher": "Farrar, Straus and Giroux",
   "publishedDate": "2014",
   "language": "en",
-  "isbn": "9780374104092"
+  "isbn": "9780374104092",
+  "bookProvider": "Open Library"
 }
 ```
 
diff --git a/src/index.d.ts b/src/index.d.ts
index ccef194..ab8558f 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -12,6 +12,7 @@
  * @property {string | undefined} [language] - The language of the book.
  * @property {string | undefined} [thumbnail] - The thumbnail image link of the book.
  * @property {string} [link] - The link of the book.
+ * @property {string} bookProvider - The provider of the book information.
  */
 /**
  * @typedef {import('./provider-resolvers.js').Providers} Providers
@@ -93,6 +94,10 @@ export type Book = {
      * - The link of the book.
      */
     link?: string;
+    /**
+     * - The provider of the book information.
+     */
+    bookProvider: string;
 };
 export type Providers = import('./provider-resolvers.js').Providers;
 export type AxiosRequestConfig = import('axios').AxiosRequestConfig;
diff --git a/src/index.js b/src/index.js
index 6cbcd3b..edfbea3 100644
--- a/src/index.js
+++ b/src/index.js
@@ -18,6 +18,7 @@ import {
  * @property {string | undefined} [language] - The language of the book.
  * @property {string | undefined} [thumbnail] - The thumbnail image link of the book.
  * @property {string} [link] - The link of the book.
+ * @property {string} bookProvider - The provider of the book information.
  */
 
 /**
diff --git a/src/providers/google.js b/src/providers/google.js
index 41470c6..f73a513 100644
--- a/src/providers/google.js
+++ b/src/providers/google.js
@@ -107,6 +107,7 @@ export async function standardize(book, id, isbn) {
     publishedDate: book.publishedDate,
     language: book.language,
     isbn,
+    bookProvider: "Google Books",
   };
 
   return standardBook;
diff --git a/src/providers/isbndb.js b/src/providers/isbndb.js
index eccd975..3dbc0e1 100644
--- a/src/providers/isbndb.js
+++ b/src/providers/isbndb.js
@@ -127,5 +127,6 @@ function standardize(book, isbn) {
     publishedDate: book.date_published,
     language: book.language,
     isbn,
+    bookProvider: "ISBNdb",
   };
 }
diff --git a/src/providers/open-library.js b/src/providers/open-library.js
index fc1435d..b3b729a 100644
--- a/src/providers/open-library.js
+++ b/src/providers/open-library.js
@@ -122,6 +122,7 @@ export async function standardize(book, isbn) {
     publishedDate: book.publish_date,
     language: formatLanguage(book.languages),
     isbn,
+    bookProvider: "Open Library",
   };
 
   return standardBook;
diff --git a/test/__snapshots__/end-to-end.test.js.snap b/test/__snapshots__/end-to-end.test.js.snap
index 03149b2..f92d20b 100644
--- a/test/__snapshots__/end-to-end.test.js.snap
+++ b/test/__snapshots__/end-to-end.test.js.snap
@@ -5,6 +5,7 @@ exports[`End to end Annihilation { name: 'default', providers: [] } 1`] = `
   "authors": [
     "Jeff VanderMeer",
   ],
+  "bookProvider": "Google Books",
   "categories": [
     "Fiction",
     "Fiction / General",
@@ -34,6 +35,7 @@ exports[`End to end Annihilation { name: 'google', providers: [Array] } 1`] = `
   "authors": [
     "Jeff VanderMeer",
   ],
+  "bookProvider": "Google Books",
   "categories": [
     "Fiction",
     "Fiction / General",
@@ -63,6 +65,7 @@ exports[`End to end Annihilation { name: 'openlibrary', providers: [Array] } 1`]
   "authors": [
     "Jeff VanderMeer",
   ],
+  "bookProvider": "Open Library",
   "categories": [
     "Nebula Award Winner",
     "award:nebula_award=novel",
@@ -125,6 +128,7 @@ exports[`End to end Fantastic Mr. Fox { name: 'default', providers: [] } 1`] = `
   "authors": [
     "Roald Dahl",
   ],
+  "bookProvider": "Google Books",
   "categories": [
     "Juvenile Fiction",
     "Juvenile Fiction / Animals / Foxes",
@@ -148,6 +152,7 @@ exports[`End to end Fantastic Mr. Fox { name: 'google', providers: [Array] } 1`]
   "authors": [
     "Roald Dahl",
   ],
+  "bookProvider": "Google Books",
   "categories": [
     "Juvenile Fiction",
     "Juvenile Fiction / Animals / Foxes",
@@ -171,6 +176,7 @@ exports[`End to end Fantastic Mr. Fox { name: 'openlibrary', providers: [Array]
   "authors": [
     "Roald Dahl",
   ],
+  "bookProvider": "Open Library",
   "categories": [
     "Animals",
     "Hunger",
@@ -226,6 +232,7 @@ exports[`End to end Transcendent Kingdom { name: 'default', providers: [] } 1`]
   "authors": [
     "Yaa Gyasi",
   ],
+  "bookProvider": "Google Books",
   "categories": [
     "Fiction",
     "Fiction / Literary",
@@ -252,6 +259,7 @@ exports[`End to end Transcendent Kingdom { name: 'google', providers: [Array] }
   "authors": [
     "Yaa Gyasi",
   ],
+  "bookProvider": "Google Books",
   "categories": [
     "Fiction",
     "Fiction / Literary",
@@ -278,6 +286,7 @@ exports[`End to end Transcendent Kingdom { name: 'openlibrary', providers: [Arra
   "authors": [
     "Yaa Gyasi",
   ],
+  "bookProvider": "Open Library",
   "categories": [
     "American literature",
     "nyt:combined-print-and-e-book-fiction=2020-09-20",
diff --git a/test/index.test.js b/test/index.test.js
index 3903cf3..aaf0c3d 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -40,6 +40,7 @@ describe("ISBN Resolver API", () => {
           "authors": [
             "Jeff VanderMeer",
           ],
+          "bookProvider": "Google Books",
           "categories": [
             "Fiction",
           ],
@@ -80,6 +81,7 @@ describe("ISBN Resolver API", () => {
       expect(book).toMatchInlineSnapshot(`
         {
           "authors": [],
+          "bookProvider": "Open Library",
           "categories": [],
           "description": "",
           "isbn": "9780374104092",
@@ -146,6 +148,7 @@ describe("ISBN Resolver API", () => {
           "authors": [
             "Aswin Pranam",
           ],
+          "bookProvider": "ISBNdb",
           "categories": undefined,
           "description": undefined,
           "isbn": "9780374104092",
@@ -237,6 +240,7 @@ describe("ISBN Resolver API", () => {
           "authors": [
             "Jeff VanderMeer",
           ],
+          "bookProvider": "Google Books",
           "categories": [
             "Fiction",
           ],
diff --git a/test/providers/google.test.js b/test/providers/google.test.js
index 0af6353..6b01d67 100644
--- a/test/providers/google.test.js
+++ b/test/providers/google.test.js
@@ -64,6 +64,7 @@ describe("resolveGoogle", () => {
         "authors": [
           "Test Author",
         ],
+        "bookProvider": "Google Books",
         "categories": [
           "Fiction",
           "Fiction / General",
@@ -150,6 +151,7 @@ describe("resolveGoogle", () => {
         "authors": [
           "Test Author",
         ],
+        "bookProvider": "Google Books",
         "categories": [
           "Fiction",
           "Fiction / General",
@@ -217,6 +219,7 @@ describe("resolveGoogle", () => {
         "authors": [
           "Test Author",
         ],
+        "bookProvider": "Google Books",
         "categories": [],
         "description": undefined,
         "isbn": "1234567890",
@@ -258,6 +261,7 @@ describe("resolveGoogle", () => {
         "authors": [
           "Test Author",
         ],
+        "bookProvider": "Google Books",
         "categories": [],
         "description": undefined,
         "isbn": "1234567890",
diff --git a/test/providers/isbndb.test.js b/test/providers/isbndb.test.js
index d8d908f..6615276 100644
--- a/test/providers/isbndb.test.js
+++ b/test/providers/isbndb.test.js
@@ -40,6 +40,7 @@ describe("resolveIsbnDb", () => {
         "authors": [
           "Test Author",
         ],
+        "bookProvider": "ISBNdb",
         "categories": [
           "Test subject",
         ],
diff --git a/test/providers/open-library.test.js b/test/providers/open-library.test.js
index f2059a1..a87125b 100644
--- a/test/providers/open-library.test.js
+++ b/test/providers/open-library.test.js
@@ -40,6 +40,7 @@ describe("resolveOpenLibrary", () => {
         "authors": [
           "Roald Dahl",
         ],
+        "bookProvider": "Open Library",
         "categories": [
           "Animals",
           "Hunger",
@@ -109,6 +110,7 @@ describe("resolveOpenLibrary", () => {
     expect(book).toMatchInlineSnapshot(`
       {
         "authors": [],
+        "bookProvider": "Open Library",
         "categories": [],
         "description": "",
         "isbn": "9780374104092",
@@ -133,7 +135,7 @@ describe("resolveOpenLibrary", () => {
     });
 
     await expect(resolveOpenLibrary(isbn, {})).rejects.toThrow(
-      `No books found with ISBN: ${isbn}`,
+      `No books found with ISBN: ${isbn}`
     );
   });
 
@@ -146,7 +148,7 @@ describe("resolveOpenLibrary", () => {
     });
 
     await expect(resolveOpenLibrary(isbn, {})).rejects.toThrow(
-      "Wrong response code: 404",
+      "Wrong response code: 404"
     );
   });
 });
@@ -188,7 +190,7 @@ describe("getAuthors", () => {
     axios.get.mockResolvedValueOnce({ status: 404 });
 
     await expect(getAuthors(rawAuthors)).rejects.toThrow(
-      "Unable to get author /authors/OL1A: 404",
+      "Unable to get author /authors/OL1A: 404"
     );
   });
 });
@@ -265,7 +267,7 @@ describe("getWorks", () => {
     axios.get.mockResolvedValueOnce({ status: 404 });
 
     await expect(getWorks({ works })).rejects.toThrow(
-      "Unable to get /works/OL1A: 404",
+      "Unable to get /works/OL1A: 404"
     );
   });
 });